Power light emitting diode and method with current density operation
View Patent ↗A light emitting diode device emitting at a wavelength of 390-415 nm has a bulk gallium and nitrogen containing substrate with an active region. The device has a current density of greater than about 175 Amps/cm 2 and an external quantum efficiency with a roll off of less than about 5% absolute efficiency.
1. A method of using a light emitting diode, the method comprising:
providing a fixture comprising the light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate having a surface region; and
at least one active region formed overlying the surface region;
a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region; and
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
2. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is characterized by a growth on a non-polar orientation.
3. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is characterized by a growth orientation in on at least one of a plurality of semi-polar crystal planes selected from the (10-1-1), (11-22), (20-21), (20-2-1), (30-31), (30-3-1), (30-32), and (30-3-2) crystal plane, and an offcut of any one of these planes within +/−5 degrees toward the c-direction and/or the a-direction.
4. The method of claim 1 , further comprising at least one phosphor operably coupled to the at least one active region to produce a white light emission.
5. The method of claim 1 , further comprising a junction area from about 0.0002 mm 2 to about 1 mm 2 .
6. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate comprises at least one region characterized by a surface dislocation density below about 10 6 cm −2 .
7. The method of claim 1 , further comprising an n-type contact electrically coupled to a first side of the at least one active region and a p-type contact electrically coupled to a second side of the at least one active region to form a vertically conducting characteristic.
8. The method of claim 1 , wherein the at least one active region is characterized by a junction temperature greater than about 100 degrees Celsius.
9. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is characterized by an optical absorption coefficient of less than about 3 cm −1 at wavelengths between about 385 nanometers and about 750 nanometers.
10. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is characterized by a resistivity less than about 0.050 ohm-cm.
11. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is an n-type semiconductor, with a carrier concentration n between about 10 16 cm −3 and 10 20 cm −3 and a carrier mobility η, in units of centimeters squared per volt-second, such that the logarithm to the base 10 of η is greater than about −0.018557n 3 +1.0671n 2 −20.599n+135.49.
12. The method of claim 1 , wherein the at least one active region comprises a total active layer thickness of at least 20 nm.
13. The method of claim 1 , wherein the current density is from 400 Amps/cm 2 to 800 Amps/cm 2 .
14. The method of claim 1 , wherein the current density is from 200 Amps/cm 2 to 1,000 Amps/cm 2 .
15. The method of claim 1 , wherein the current density is from 500 Amps/cm 2 to 1,000 Amps/cm 2 .
16. The method of claim 1 , wherein the current density is from 1,000 Amps/cm 2 to 2,000 Amps/cm 2 .
17. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is characterized by a growth on a polar orientation.
18. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is grown epitaxially, ammonothermally, by hydride vapor phase-epitaxy, by metalorganic chemical vapor deposition, by molecular beam epitaxy, by liquid phase epitaxy, by a flux method, or by a combination of any of the foregoing.
19. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate comprises at least one region characterized by a surface dislocation density below about 10 7 cm −2 .
20. The method of claim 1 , wherein the light emitting diode is operable in a continuous wave mode.
21. The method of claim 1 , wherein the light emitting diode is operable in a pulsed mode.
22. The method of claim 1 , wherein the light emitting diode is characterized by a lumens per active junction area greater than 300 lm/mm 2 , for a warm white emission with a correlated color temperature (CCT) of less than about 5,000K, and a color rendering index (CRI) greater than 75.
23. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is characterized by a growth on a polar orientation.
24. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is characterized by a growth on a c-plane orientation.
25. A method of using a light emitting diode, the method comprising:
providing a fixture comprising the light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate comprising a surface region characterized by a c-plane orientation;
one or more n-type epitaxial layers overlying the surface region;
at least one active region formed overlying the one or more n-type epitaxial layers, wherein the at least one active region comprises one or more active layers, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region;
one or more p-type epitaxial layers overlying the at least one active region;
at least one reflective p-type contact overlying the one or more p-type epitaxial layers and electrically coupled to a first side of the at least one active region; and
at least one n-type contact electrically coupled to a second side of the at least one active region;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
26. The method of claim 25 , wherein the c-plane is selected from the (0001) plane, the (000-1) plane, and an offcut of any one of these planes.
27. The method of claim 25 , further comprising at least one phosphor operably coupled to the at least one active region to produce a white light emission.
28. The method of claim 25 , further comprising a junction area from about 0.0002 mm 2 to about 1 mm 2 .
29. The method of claim 25 , wherein the bulk gallium and nitrogen containing substrate comprises at least one region characterized by a surface dislocation density below about 10 6 cm −2 .
30. The method of claim 25 , wherein the active region is characterized by a junction temperature greater than about 100 degrees Celsius.
31. The method of claim 25 , wherein the bulk gallium and nitrogen containing substrate is characterized by an optical absorption coefficient of less than about 3 cm −1 at wavelengths between about 385 nanometers and about 750 nanometers.
32. The method of claim 25 , wherein the bulk gallium and nitrogen containing substrate is characterized by a resistivity less than about 0.050 ohm-cm.
33. The method of claim 25 , wherein the bulk gallium and nitrogen containing substrate is an n-type semiconductor, with a carrier concentration n between about 10 16 cm −3 and 10 20 cm −3 and a carrier mobility η, in units of centimeters squared per volt-second, such that the logarithm to the base 10 of η is greater than about −0.018557n 3 +1.0671n 2 -20.599n+135.49.
34. The method of claim 25 , wherein the at least one active region comprises a total active layer thickness of at least 20 nm.
35. The method of claim 25 , wherein the current density is from 400 Amps/cm 2 to 800 Amps/cm 2 .
36. The method of claim 25 , wherein the current density is from 200 Amps/cm 2 to 1,000 Amps/cm 2 .
37. The method of claim 25 , wherein the current density is from 500 Amps/cm 2 to 1,000 Amps/cm 2 .
38. The method of claim 25 , wherein the current density is from 1,000 Amps/cm 2 to 2,000 Amps/cm 2 .
39. The method of claim 25 , wherein the at least one n-type contact is adjacent the at least one n-type epitaxial layer, is adjacent the substrate, or a combination thereof.
40. The method of claim 25 , wherein the bulk gallium and nitrogen containing substrate is grown epitaxially, ammonothermally, by hydride vapor phase-epitaxy, by metalorganic chemical vapor deposition, by molecular beam epitaxy, by liquid phase epitaxy, by a flux method, or by a combination of any of the foregoing.
41. The method of claim 25 , wherein the bulk gallium and nitrogen containing substrate comprises at least one region characterized by a surface dislocation density below about 10 7 cm −2 .
42. The method of claim 25 , wherein the light emitting diode is operable in a continuous wave mode.
43. The method of claim 25 , wherein the light emitting diode is operable in a pulsed mode.
44. The method of claim 25 , wherein the light emitting diode is characterized by a lumens per active junction area of greater than 300 lm/mm 2 , for a warm white emission with a correlated color temperature (CCT) of less than about 5,000K, and a color rendering index (CRI) greater than 75.
45. A method of using a light emitting diode, the method comprising:
providing a fixture comprising a light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate having a surface region characterized by a semipolar orientation; and
at least one active region formed overlying the surface region, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
46. The method of claim 45 , wherein the semipolar orientation is selected from the (10-1-1), (11-22), (20-21), (20-2-1), (30-31), (30-3-1), (30-32), and (30-3-2) crystal plane, and an offcut of any one of these planes within +/−5 degrees toward the c-direction and/or the a-direction.
47. The method of claim 45 , further comprising at least one phosphor operably coupled to the at least one active region to produce a white light emission.
48. The method of claim 45 , further comprising a junction area from about 0.0002 mm 2 to about 1 mm 2 .
49. The method of claim 45 , wherein the bulk gallium and nitrogen containing substrate comprises at least one region characterized by a surface dislocation density below about 10 6 cm −2 .
50. The method of claim 45 , further comprising an n-type contact electrically coupled to a first side of the at least one active region and a p-type contact electrically coupled to a second side of the at least one active region to form a vertically conducting characteristic.
51. The method of claim 45 , wherein the active region is characterized by a junction temperature greater than about 100 degrees Celsius.
52. The method of claim 45 , wherein the bulk gallium and nitrogen containing substrate is characterized by an optical absorption coefficient of less than about 3 cm −1 at wavelengths between about 385 nanometers and about 750 nanometers.
53. The method of claim 45 , wherein the bulk gallium and nitrogen containing substrate is characterized by a resistivity less than about 0.050 ohm-cm.
54. The method of claim 45 , wherein the bulk gallium and nitrogen containing substrate is an n-type semiconductor, with a carrier concentration n between about 10 16 cm −3 and 10 20 cm −3 and a carrier mobility η, in units of centimeters squared per volt-second, such that the logarithm to the base 10 of η is greater than about −0.018557n 3 +1.0671n 2 -20.599n+135.49.
55. The method of claim 45 , wherein the at least one active region comprises a total active layer thickness of at least 20 nm.
56. The method of claim 45 , wherein the current density is from 400 Amps/cm 2 to 800 Amps/cm 2 .
57. The method of claim 45 , wherein the current density is from 200 Amps/cm 2 to 1,000 Amps/cm 2 .
58. The method of claim 45 , wherein the current density is from 500 Amps/cm 2 to 1,000 Amps/cm 2 .
59. The method of claim 45 , wherein the current density is from 1,000 Amps/cm 2 to 2,000 Amps/cm 2 .
60. The method of claim 45 , wherein the bulk gallium and nitrogen containing substrate is grown epitaxially, ammonothermally, by hydride vapor phase-epitaxy, by metalorganic chemical vapor deposition, by molecular beam epitaxy, by liquid phase epitaxy, by a flux method, or by a combination of any of the foregoing.
61. The method of claim 45 , wherein the bulk gallium and nitrogen containing substrate comprises at least one region characterized by a surface dislocation density below about 10 7 cm −2 .
62. The method of claim 45 , wherein the light emitting diode is operable in a continuous wave mode.
63. The method of claim 45 , wherein the light emitting diode is operable in a pulsed mode.
64. The method of claim 45 , wherein the light emitting diode is characterized by a lumens per active junction area greater than 300 lm/mm 2 , for a warm white emission with a correlated color temperature (CCT) of less than about 5,000K, and a color rendering index (CRI) greater than 75.
65. A method of using a light emitting diode, the method comprising:
providing a fixture comprising a light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate having a surface region characterized by a nonpolar orientation; and
at least one active region formed overlying the surface region, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
66. The method of claim 65 , wherein the nonpolar orientation is selected from the (10-10) plane and a miscut from 0.1 degrees to 3 degrees toward the (0001) plane or the (1-210) plane.
67. The method of claim 65 , further comprising at least one phosphor operably coupled to the at least one active region to produce a white light emission.
68. The method of claim 65 , further comprising a junction area from about 0.0002 mm 2 to about 1 mm 2 .
69. The method of claim 65 , wherein the bulk gallium and nitrogen containing substrate comprises at least one region characterized by a surface dislocation density below about 10 6 cm −2 .
70. The method of claim 65 , further comprising an n-type contact electrically coupled to a first side of the at least one active region and a p-type contact electrically coupled to a second side of the at least one active region to form a vertically conducting characteristic.
71. The method of claim 65 , wherein the active region is characterized by a junction temperature greater than about 100 degrees Celsius.
72. The method of claim 65 , wherein the bulk gallium and nitrogen containing substrate is characterized by an optical absorption coefficient of less than about 3 cm −1 at wavelengths between about 385 nanometers and about 750 nanometers.
73. The method of claim 65 , wherein the bulk gallium and nitrogen containing substrate is characterized by a resistivity less than about 0.050 ohm-cm.
74. The method of claim 65 , wherein the bulk gallium and nitrogen containing substrate is an n-type semiconductor, with a carrier concentration n between about 10 16 cm −3 and 10 20 cm −3 and a carrier mobility η, in units of centimeters squared per volt-second, such that the logarithm to the base 10 of η is greater than about −0.018557n 3 +1.0671n 2 -20.599n+135.49.
75. The method of claim 65 , wherein the at least one active region comprises a total active layer thickness of at least 20 nm.
76. The method of claim 65 , wherein the current density is from 400 Amps/cm 2 to 800 Amps/cm 2 .
77. The method of claim 65 , wherein the current density is from 200 Amps/cm 2 to 1,000 Amps/cm 2 .
78. The method of claim 65 , wherein the current density is from 500 Amps/cm 2 to 1,000 Amps/cm 2 .
79. The method of claim 65 , wherein the current density is from 1,000 Amps/cm 2 to 2,000 Amps/cm 2 .
80. The method of claim 65 , wherein the bulk gallium and nitrogen containing substrate is grown epitaxially, ammonothermally, by hydride vapor phase-epitaxy, by metalorganic chemical vapor deposition, by molecular beam epitaxy, by liquid phase epitaxy, by a flux method, or by a combination of any of the foregoing.
81. The method of claim 65 , wherein the bulk gallium and nitrogen containing substrate comprises at least one region characterized by a surface dislocation density below about 10 7 cm −2 .
82. The method of claim 65 , wherein the light emitting diode is operable in a continuous wave mode.
83. The method of claim 65 , wherein the light emitting diode is operable in a pulsed mode.
84. The method of claim 65 , wherein the light emitting diode is characterized by a lumens per active junction area greater than 300 lm/mm 2 , for a warm white emission with a correlated color temperature (CCT) of less than about 5,000K, and a color rendering index (CRI) greater than 75.
85. A method of using a lighting fixture, the method comprising:
providing a lighting fixture comprising a light emitting diode, wherein the light emitting diode comprises:
a bulk gallium and nitrogen containing substrate having a surface region; and
at least one active region formed overlying the surface region; a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region; and
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
86. A method of using a lighting fixture, the method comprising:
providing a lighting fixture comprising a light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate comprising a surface region characterized by a c-plane orientation;
one or more n-type epitaxial layers overlying the surface region;
at least one active region formed overlying the one or more n-type epitaxial layers, wherein the at least one active region comprises one or more active layers, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region;
one or more p-type epitaxial layers overlying the at least one active region;
at least one reflective p-type contact overlying the one or more p-type epitaxial layers and electrically coupled to a first side of the at least one active region; and
at least one n-type contact electrically coupled to a second side of the at least one active region;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
87. A method of using a lighting fixture, the method comprising:
providing a lighting fixture comprising a light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate having a surface region characterized by a semipolar orientation; and
at least one active region formed overlying the surface region, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
88. A method of using a lighting fixture, the method comprising:
providing a lighting fixture comprising a light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate having a surface region characterized by a nonpolar orientation; and
at least one active region formed overlying the surface region, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
89. A method of using a lamp comprising, the method comprising:
providing a lamp comprising a light emitting diode, wherein the light emitting diode comprises:
a bulk gallium and nitrogen containing substrate having a surface region; and
at least one active region formed overlying the surface region; a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region; and
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
90. The method of claim 89 , wherein the lamp is a replacement lamp.
91. The method of claim 89 , wherein the lamp conforms to a form factor selected from an A-lamp, a fluorescent tube, a compact fluorescent lamp (CFL), a metallic reflector (MR) lamp, an MR16 lamp, a parabolic reflector (PAR) lamp, a reflector bulb (R), a single end quartz halogen lamp, a double end quartz halogen lamp, a candelabra, a globe bulb, a high bay lamp, a troffer lamp, and a cobra head lamp.
92. A method of using a lamp, the method comprising:
providing a lamp comprising the light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate comprising a surface region characterized by a c-plane orientation;
one or more n-type epitaxial layers overlying the surface region;
at least one active region formed overlying the one or more n-type epitaxial layers, wherein the at least one active region comprises one or more active layers, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region;
one or more p-type epitaxial layers overlying the at least one active region;
at least one reflective p-type contact overlying the one or more p-type epitaxial layers and electrically coupled to a first side of the at least one active region; and
at least one n-type contact electrically coupled to a second side of the at least one active region;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
93. The method of claim 92 , wherein the lamp is a replacement lamp.
94. The method of claim 92 , wherein the lamp conforms to a form factor selected from an A-lamp, a fluorescent tube, a compact fluorescent lamp (CFL), a metallic reflector (MR) lamp, an MR16 lamp, a parabolic reflector (PAR) lamp, a reflector bulb (R), a single end quartz halogen lamp, a double end quartz halogen lamp, a candelabra, a globe bulb, a high bay lamp, a troffer lamp, and a cobra head lamp.
95. A method using a lamp comprising a light emitting diode, the method comprising:
providing a lamp comprising a light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate having a surface region characterized by a semipolar orientation; and
at least one active region formed overlying the surface region, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
96. The method of claim 95 , wherein the lamp is a replacement lamp.
97. The method of claim 95 , wherein the lamp conforms to a form factor selected from an A-lamp, a fluorescent tube, a compact fluorescent lamp (CFL), a metallic reflector (MR) lamp, an MR16 lamp, a parabolic reflector (PAR) lamp, a reflector bulb (R), a single end quartz halogen lamp, a double end quartz halogen lamp, a candelabra, a globe bulb, a high bay lamp, a troffer lamp, and a cobra head lamp.
98. A method of using a lamp, the method comprising:
providing a lamp comprising a light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate having a surface region characterized by a nonpolar orientation; and
at least one active region formed overlying the surface region, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
99. The method of claim 98 , wherein the lamp is a replacement lamp.
100. The method of claim 98 , wherein the lamp conforms to a form factor selected from an A-lamp, a fluorescent tube, a compact fluorescent lamp (CFL), a metallic reflector (MR) lamp, an MR16 lamp, a parabolic reflector (PAR) lamp, a reflector bulb (R), a single end quartz halogen lamp, a double end quartz halogen lamp, a candelabra, a globe bulb, a high bay lamp, a troffer lamp, and a cobra head lamp.
101. A method of using a lamp, wherein the lamp conforms to a MR16 form factor and comprises a light emitting diode, the method comprising:
providing the lamp conforming to a MR16 form factor and comprising a light emitting diode, the light emitting diode comprising:
a bulk gallium and nitrogen containing substrate having a surface region characterized by a c-plane orientation;
at least one active region formed overlying the surface region, a current density from 175 Amps/cm 2 to 2,000 Amps/cm 2 characterizing the at least one active region; and
at least one phosphor operably coupled to the at least one active region to produce a white light emission;
wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; and
emitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.
102. The method of claim 101 , wherein the current density is from 400 Amps/cm 2 to 800 Amps/cm 2 .
103. The method of claim 101 , wherein the current density is from 200 Amps/cm 2 to 1,000 Amps/cm 2 .
104. The method of claim 101 , wherein the current density is from 500 Amps/cm 2 to 1,000 Amps/cm 2 .
105. The method of claim 101 , wherein the current density is from 1,000 Amps/cm 2 to 2,000 Amps/cm 2 .
106. The method of claim 101 , wherein the light emitting diode is characterized by a lumens per active junction area of greater than 300 lm/mm 2 , for a warm white emission with a correlated color temperature (CCT) of less than about 5,000K, and a color rendering index (CRI) greater than 75.