Photodetectors and optically pumped emitters based on III-nitride multiple-quantum-well structures
View Patent ↗The design and operation of a p-i-n device, operating in a sequential resonant tunneling condition for use as a photodetector and an optically pumped emitter, is disclosed. The device contains III-nitride multiple-quantum-well (MQW) layers grown between a III-nitride p-n junction. Transparent ohmic contacts are made on both p and n sides. The device operates under a certain electrical bias that makes the energy level of the first excitation state in each well layer correspond with the energy level of the ground state in the adjoining well layer. The device works as a high-efficiency and high-speed photodetector with photo-generated carriers transported through the active MQW region by sequential resonant tunneling. In a sequential resonant tunneling condition, the device also works as an optically pumped infrared emitter that emits infrared photons with energy equal to the energy difference between the first excitation state and the ground state in the MQWs.
1. A sequential resonant tunneling device for back-side illumination, comprising an alternating semiconductor layer structure as follows:
Thick-
ness
Material
(nm)
Dopant
Doping level
c-plane (0001)
Not
Not
Not limited
sapphire
limited
limited
substrate
AlN
10
un-doped
0
Al 0.2 Ga 0.8 N
1000
silicon
1 × 10 18 cm −3
Al 0.27 Ga 0.73 N
5
undoped
0
GaN
4
undoped
0
Al 0.27 Ga 0.73 N
7
undoped
0
QW unit
{open oversize brace}
GaN
4
undoped
0
.
.
.
.
.
.
.
.
30 QW units
{open oversize brace}
.
.
.
.
Al 0.27 Ga 0.73 N
7
undoped
0
GaN
4
undoped
0
Al 0.27 Ga 0.73 N
5
undoped
0
GaN
300
magne-
1 × 10 18 cm −3
sium.
2. The sequential resonant tunneling device according to claim 1 , further comprising metal contacts on surfaces of n and p type semiconductors.
3. A sequential resonant tunneling device for front-side illumination, comprising a multi-layered semiconductor structure, as follows:
Thickness
Material
(nm)
Dopant
Doping level
c-plane
Not limited
Not limited
Not limited
(0001) sapphire substrate
AlN
10
Undoped
0
GaN
1000
Silicon
1 × 10 18 cm −3
Al 0.25 Ga 0.75 N
5
Undoped
0
GaN
4
Undoped
0
Al 0.25 Ga 0.75 N
7
Undoped
0
QW unit A
{open oversize brace}
GaN
4
Undoped
0
.
.
.
.
.
.
.
.
30 periods
{open oversize brace}
.
.
.
.
QW unit A
Al 0.27 Ga 0.73 N
7
Undoped
0
GaN
4
Undoped
0
Al 0.25 Ga 0.75 N
4
magnesium
1 × 10 18 cm −3
QW unit B
{open oversize brace}
Al 0.33 Ga 0.67 N
4
magnesium
1 × 10 18 cm −3
.
.
.
.
.
.
.
.
25 periods
{open oversize brace}
.
.
.
.
QW unit B
Al 0.25 Ga 0.75 N
4
magnesium
1 × 10 18 cm −3
Al 0.33 Ga 0.67 N
4
magnesium
1 × 10 18 cm −3
GaN
10
magnesium
1 × 10 18 cm −3 .
4. The sequential resonant tunneling device according to claim 3 , further comprising metal contacts on surfaces of n and p type semiconductors.
5. A sequential resonant tunneling device for front-side illumination comprising a multilayered semiconductor structure as follows:
Thickness
Material
(nm)
Dopant
Doping level
6H-SiC
Not
p-type
1 × 10 18 cm −3
substrate
limited
AlN
10
un-doped
0
Al 0.27 Ga 0.73 N
5
Undoped
0
GaN
4
Undoped
0
Al 0.27 Ga 0.73 N
7
Undoped
0
QW unit
{open oversize brace}
GaN
4
Undoped
0
.
.
.
.
.
.
.
.
30 periods
{open oversize brace}
.
.
.
.
QW units
Al 0.27 Ga 0.73 N
7
Undoped
0
GaN
4
Undoped
0
Al 0.27 Ga 0.73 N
5
Undoped
0
Al 0.2 Ga 0.8 N
1000
Silicon
1 × 10 18 cm −3
GaN
10
Silicon
1 × 10 18 cm −3 .
6. The sequential resonant tunneling device according to claim 5 , further comprising metal contacts on surfaces of n and p type semiconductors.