EXPONENTIAL DOPING IN LATTICE-MATCHED DILUTE NITRIDE PHOTOVOLTAIC CELLS
Dilute nitride subcells with graded doping are disclosed. Dilute nitride subcells having graded doping display improved efficiency, short circuit current density, and open circuit voltage.
1 . A dilute nitride subcell, comprising:
an (In)GaAs back surface field overlying the p-type substrate;
a dilute nitride base overlying the (In)GaAs back surface field, wherein,
the dilute nitride base comprises a first base portion, a second base portion, and an interface between the first base portion and the second base portion; and
the dilute nitride base comprises GaInNAsSb; and
an (In)GaAs emitter overlying the dilute nitride base, wherein,
the (In)GaAs emitter comprises an n-type doping profile characterized by a constant dopant concentration within a range from 2E17 atoms/cm 3 to 8E18 atoms/cm 3 ;
the first base portion extends from the (In)GaAs emitter to the second base portion;
the second base portion extends from the first base portion to the (In)GaAs back surface field;
the first base portion is intrinsically doped; and
the second base portion comprises a p-type dopant concentration that increases exponentially from a dopant concentration within a range from 5E15 atoms/cm 3 to 5E16 atoms/cm 3 at the interface to within a range from 1E18 atoms/cm 3 to 8E18 atoms/cm 3 at the (In)GaAs back surface field;
each of the (In)GaAs emitter, the dilute nitride base, and the (In)GaAs back surface field is lattice matched to a p-type GaAs or (Sn,Si)Ge substrate; and
the dilute nitride subcell is characterized by a band gap within a range from 0.9 eV to 1.25 eV.
2 . A dilute nitride subcell of claim 1 , wherein,
the (In)GaAs emitter is characterized by a thickness from 50 nm to 600 nm; and
the dilute nitride base is characterized by a thickness from 400 nm to 3,500 nm.
3 . The dilute nitride subcell of claim 1 , wherein,
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.19, 0.040≦y≦0.051, and 0.010≦z≦0.018; and the dilute nitride base is characterized by a bandgap from 0.89 eV to 0.92 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.010≦x≦0.16, 0.028≦y≦0.037, and 0.005≦z≦0.016; and the dilute nitride base is characterized by a bandgap from 0.95 eV to 0.98 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.075≦x≦0.081, 0.040≦y≦0.051, and 0.010≦z≦0.018; and the dilute nitride base is characterized by a bandgap from 1.111 eV to 1.117 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.024, 0.077≦y≦0.085, and 0.011≦z≦0.015; and the dilute nitride base is characterized by a bandgap from 1.10 eV to 1.14 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.068≦x≦0.078, 0.010≦y≦0.017, and 0.011≦z≦0.004; and the dilute nitride base is characterized by a bandgap from 1.15 eV to 1.16 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.011≦x≦0.015, 0.04≦y≦0.06, and 0.016≦z≦0.020; and the dilute nitride base is characterized by a bandgap from 1.14 eV to 1.18 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.075≦x≦0.082, 0.016≦y≦0.019, and 0.004≦z≦0.010; and the dilute nitride base is characterized by a bandgap from 1.12 eV to 1.16 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.06≦x≦0.09, 0.01≦y≦0.025, and 0.004≦z≦0.014; and the dilute nitride base is characterized by a bandgap from 1.12 eV to 1.16 eV.
4 . The dilute nitride subcell of claim 1 , wherein,
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.012≦x≦0.016, 0.033≦y≦0.037, and 0.016≦z≦0.020; and the dilute nitride base is characterized by a bandgap from 1.18 eV to 1.22 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.026≦x≦0.030, 0.024≦y≦0.018, and 0.005≦z≦0.009; and the dilute nitride base is characterized by a bandgap from 1.18 eV to 1.22 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.0.024, 0.077≦y≦0.085, and 0.010≦z≦0.016; and the dilute nitride base is characterized by a bandgap from 1.118 eV to 1.122 eV.
5 . A dilute nitride subcell, comprising:
an (In)GaAs back surface field overlying the n-type substrate;
a dilute nitride base overlying the (In)GaAs back surface field, wherein,
the dilute nitride base comprises a first base portion, a second base portion, and an interface between the first base portion and the second base portion; and
the dilute nitride base comprises GaInNAsSb;
an (In)GaAs emitter overlying the dilute nitride base, wherein,
the (In)GaAs emitter comprises a p-type doping profile characterized by a constant p-type dopant concentration within a range from 2E17 atoms/cm 3 to 8E18 atoms/cm 3 ;
the first base portion extends from the (In)GaAs emitter to the second base portion;
the second base portion extends from the first base portion to the (In)GaAs back surface field;
the first base portion is intrinsically doped; and
the second base portion comprises an n-type dopant concentration that increases exponentially from a dopant concentration within a range from 5E15 atoms/cm 3 to 5E16 atoms/cm 3 at the interface to within a range from 0.1E18 atoms/cm 3 to 8E18 atoms/cm 3 at the (In)GaAs back surface field;
each of the (In)GaAs emitter, the dilute nitride base, and the (In)GaAs back surface field is lattice matched to an n-type GaAs or (Sn,Si)Ge substrate; and
the dilute nitride subcell is characterized by a band gap within a range from 0.9 eV to 1.25 eV.
6 . A dilute nitride subcell of claim 5 , wherein,
the (In)GaAs emitter is characterized by a thickness from 50 nm to 600 nm; and
the dilute nitride base is characterized by a thickness from 400 nm to 3,500 nm.
7 . The dilute nitride subcell of claim 5 , wherein,
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.19, 0.040≦y≦0.051, and 0.010≦z≦0.018; and the dilute nitride base is characterized by a bandgap from 0.89 eV to 0.92 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.010≦x≦0.16, 0.028≦y≦0.037, and 0.005≦z≦0.016; and the dilute nitride base is characterized by a bandgap from 0.95 eV to 0.98 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.075≦x≦0.081, 0.040≦y≦0.051, and 0.010≦z≦0.018; and the dilute nitride base is characterized by a bandgap from 1.111 eV to 1.117 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.024, 0.077≦y≦0.085, and 0.011≦z≦0.015; and the dilute nitride base is characterized by a bandgap from 1.10 eV to 1.14 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.068≦x≦0.078, 0.010≦y≦0.017, and 0.011≦z≦0.004; and the dilute nitride base is characterized by a bandgap from 1.15 eV to 1.16 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.011≦x≦0.015, 0.04≦y≦0.06, and 0.016≦z≦0.020; and the dilute nitride base is characterized by a bandgap from 1.14 eV to 1.18 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.075≦x≦0.082, 0.016≦y≦0.019, and 0.004≦z≦0.010; and the dilute nitride base is characterized by a bandgap from 1.12 eV to 1.16 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.06≦x≦0.09, 0.01≦y≦0.025, and 0.004≦z≦0.014; and the dilute nitride base is characterized by a bandgap from 1.12 eV to 1.16 eV.
8 . The dilute nitride subcell of claim 5 , wherein,
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.012≦x≦0.016, 0.033≦y≦0.037, and 0.016≦z≦0.020; and the dilute nitride base is characterized by a bandgap from 1.18 eV to 1.22 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.026≦x≦0.030, 0.024≦y≦0.018, and 0.005≦z≦0.009; and the dilute nitride base is characterized by a bandgap from 1.18 eV to 1.22 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.0.024, 0.077≦y≦0.085, and 0.010≦z≦0.016; and the dilute nitride base is characterized by a bandgap from 1.118 eV to 1.122 eV.
9 . A dilute nitride subcell, comprising:
an (In)GaAs back surface field overlying the p-type substrate;
a dilute nitride base overlying the (In)GaAs back surface field, wherein
the dilute nitride base comprises GaInNAsSb;
an (In)GaAs emitter overlying the dilute nitride base,
the (In)GaAs emitter comprises a n-type doping profile characterized by a constant dopant concentration within a range from 2E17 atoms/cm 3 to 8E18 atoms/cm 3 ;
the dilute nitride base comprises a n-type doping profile that increases from an n-type dopant concentration within a range from 1E15 atoms/cm 3 to 5E16 atoms/cm 3 at the interface to within a range from 0.1E18 atoms/cm 3 to 8E18 atoms/cm 3 at the (In)GaAs back surface field, wherein,
the n-type doping profile comprises a linear profile, an exponential profile, a constant profile, a step-wise profile, or a combination of any of the foregoing;
each of the (In)GaAs emitter, the dilute nitride base, and the (In)GaAs back surface field is lattice matched to a p-type GaAs or (Sn,Si)Ge substrate; and
the dilute nitride subcell is characterized by a band gap within a range from 0.9 eV to 1.25 eV.
10 . A dilute nitride subcell of claim 9 , wherein,
the (In)GaAs emitter is characterized by a thickness from 50 nm to 600 nm; and
the dilute nitride base is characterized by a thickness from 400 nm to 3,500 nm.
11 . The dilute nitride subcell of claim 9 , wherein,
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.19, 0.040≦y≦0.051, and 0.010≦z≦0.018; and the dilute nitride base is characterized by a bandgap from 0.89 eV to 0.92 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.010≦x≦0.16, 0.028≦y≦0.037, and 0.005≦z≦0.016; and the dilute nitride base is characterized by a bandgap from 0.95 eV to 0.98 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.075≦x≦0.081, 0.040≦y≦0.051, and 0.010≦z≦0.018; and the dilute nitride base is characterized by a bandgap from 1.111 eV to 1.117 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.024, 0.077≦y≦0.085, and 0.011≦z≦0.015; and the dilute nitride base is characterized by a bandgap from 1.10 eV to 1.14 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.068≦x≦0.078, 0.010≦y≦0.017, and 0.011≦z≦0.004; and the dilute nitride base is characterized by a bandgap from 1.15 eV to 1.16 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.011≦x≦0.015, 0.04≦y≦0.06, and 0.016≦z≦0.020; and the dilute nitride base is characterized by a bandgap from 1.14 eV to 1.18 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.075≦x≦0.082, 0.016≦y≦0.019, and 0.004≦z≦0.010; and the dilute nitride base is characterized by a bandgap from 1.12 eV to 1.16 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.06≦x≦0.09, 0.01≦y≦0.025, and 0.004≦z≦0.014; and the dilute nitride base is characterized by a bandgap from 1.12 eV to 1.16 eV.
12 . The dilute nitride subcell of claim 9 , wherein,
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.012≦x≦0.016, 0.033≦y≦0.037, and 0.016≦z≦0.020; and the dilute nitride base is characterized by a bandgap from 1.18 eV to 1.22 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.026≦x≦0.030, 0.024≦y≦0.018, and 0.005≦z≦0.009; and the dilute nitride base is characterized by a bandgap from 1.18 eV to 1.22 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.0.024, 0.077≦y≦0.085, and 0.010≦z≦0.016; and the dilute nitride base is characterized by a bandgap from 1.118 eV to 1.122 eV.
13 . A dilute nitride subcell, comprising:
an (In)GaAs back surface field overlying the n-type substrate;
a dilute nitride base overlying the (In)GaAs back surface field, wherein the dilute nitride base comprises GaInNAsSb;
an (In)GaAs emitter overlying the dilute nitride base,
wherein,
the (In)GaAs emitter comprises a p-type doping profile characterized by a constant p-type dopant concentration within a range from 2E17 atoms/cm 3 to 8E18 atoms/cm 3 ;
the dilute nitride base comprises a p-type doping profile that increases from a dopant concentration within a range from 1E15 atoms/cm 3 to 5E16 atoms/cm 3 at the interface to within a range from 0.1E18 atoms/cm 3 to 8E18 atoms/cm 3 at the dilute nitride base-(In)GaAs back surface field, wherein,
the p-type doping profile comprises a linear profile, an exponential profile, a constant profile, a step-wise profile, or a combination of any of the foregoing;
each of the (In)GaAs emitter, the dilute nitride base, and the (In)GaAs back surface field is lattice matched to a p-type GaAs or (Sn,Si)Ge substrate; and
the dilute nitride subcell is characterized by a band gap within a range from 0.9 eV to 1.25 eV.
14 . A dilute nitride subcell of claim 13 , wherein,
the (In)GaAs emitter is characterized by a thickness from 50 nm to 600 nm; and
the dilute nitride base is characterized by a thickness from 400 nm to 3,500 nm.
15 . The dilute nitride subcell of claim 13 , wherein,
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.19, 0.040≦y≦0.051, and 0.010≦z≦0.018; and the dilute nitride base is characterized by a bandgap from 0.89 eV to 0.92 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.010≦x≦0.16, 0.028≦y≦0.037, and 0.005≦z≦0.016; and the dilute nitride base is characterized by a bandgap from 0.95 eV to 0.98 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.075≦x≦0.081, 0.040≦y≦0.051, and 0.010≦z≦0.018; and the dilute nitride base is characterized by a bandgap from 1.111 eV to 1.117 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.024, 0.077≦y≦0.085, and 0.011≦z≦0.015; and the dilute nitride base is characterized by a bandgap from 1.10 eV to 1.14 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.068≦x≦0.078, 0.010≦y≦0.017, and 0.011≦z≦0.004; and the dilute nitride base is characterized by a bandgap from 1.15 eV to 1.16 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.011≦x≦0.015, 0.04≦y≦0.06, and 0.016≦z≦0.020; and the dilute nitride base is characterized by a bandgap from 1.14 eV to 1.18 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.075≦x≦0.082, 0.016≦y≦0.019, and 0.004≦z≦0.010; and the dilute nitride base is characterized by a bandgap from 1.12 eV to 1.16 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.06≦x≦0.09, 0.01≦y≦0.025, and 0.004≦z≦0.014; and the dilute nitride base is characterized by a bandgap from 1.12 eV to 1.16 eV.
16 . The dilute nitride subcell of claim 13 , wherein,
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.012≦x≦0.016, 0.033≦y≦0.037, and 0.016≦z≦0.020; and the dilute nitride base is characterized by a bandgap from 1.18 eV to 1.22 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.026≦x≦0.030, 0.024≦y≦0.018, and 0.005≦z≦0.009; and the dilute nitride base is characterized by a bandgap from 1.18 eV to 1.22 eV; or
the dilute nitride base comprises Ga 1-x In x N y As 1-y-z Sb z wherein 0.016≦x≦0.0.024, 0.077≦y≦0.085, and 0.010≦z≦0.016; and the dilute nitride base is characterized by a bandgap from 1.118 eV to 1.122 eV.
17 . A multijunction photovoltaic cell comprising the dilute nitride subcell of claim 1 .
18 . A multijunction photovoltaic cell comprising the dilute nitride subcell of claim 5 .
19 . A multijunction photovoltaic cell comprising the dilute nitride subcell of claim 7 .
20 . A multijunction photovoltaic cell comprising the dilute nitride subcell of claim 13 .