Isoelectronic co-doping
AssigneeMidwest Research Institute
InventorAngelo Mascarenhas
Life of this patent
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Abstract
Isoelectronic co-doping of semiconductor compounds and alloys with deep acceptors and deep donors is used to decrease bandgap, to increase concentration of the dopant constituents in the resulting alloys, and to increase carrier mobilities lifetimes. Group III-V compounds and alloys, such as GaAs and GaP, are isoelectronically co-doped with, for example, N and Bi, to customize solar cells, thermal voltaic cells, light emitting diodes, photodetectors, and lasers on GaP, InP, GaAs, Ge, and Si substrates. Isoelectronically co-doped Group II-VI compounds and alloys are also included.
Claims169
A method of modifying a semiconductor compound or alloy comprising host atoms in a host crystal lattice to have a lower effective bandgap than the semiconductor compound or alloy has prior to modification, comprising:
- isoelectronically co-doping the semiconductor compound or alloy with a first isoelectronic dopant comprising atoms that form isoelectronic electron traps in the host crystal lattice that behave as deep acceptors and with a second isoelectronic dopant comprising atoms that form isoelectronic hole traps in the host crystal lattice that behave as deep donors, such that content of the first isoelectronic dopant in the semiconductor compound or alloy is more than 1 at. % and content of the second isoelectronic dopant in the semiconductor compound or alloy is more than 1 at. %.
A method of modifying a Group III-V semiconductor compound or alloy to have a lower effective bandgap than the Group III-V semiconductor compound or alloy has prior to modification, comprising:
- isoelectronically co-doping the Group III-V compound or alloy with more than 1 at. % of a deep acceptor element and more than 1 at. % of a deep donor element.
A semiconductor material for use as an active cell in a semiconductor device, the material comprising:
- a semiconductor compound or alloy comprising host atoms in a host crystal lattice with an effective bandgap that is modified by isoelectronic co-doping with more than 1 at. % of a first isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep acceptors and more than 1 at. % of a second isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep donors to lower the effective bandgap of the semiconductor material.
A monolithic, quadruple junction solar cell, comprising:
- a first cell comprising Ge with a bandgap of about 0.67 eV;
- a second cell comprising GaAs that is isoelectronically co-doped with a deep acceptor element and a deep donor element to have an effective bandgap of about 1.05 eV on the first cell;
- a third cell comprising GaAs with a bandgap of about 1.42 eV on the second cell;
- and
- a fourth cell comprising InGaP with a bandgap of about 1.90 eV on the third cell.
A two-junction tandem solar cell, comprising:
- a bottom cell comprising a Si substrate with a bandgap of about 1.1 eV and that has a charge-doped junction;
- and
- a top cell on the bottom cell, said top cell comprising GaP that is isoelectronically co-doped with a deep acceptor element and a deep donor element to have an effective bandgap of about 1.75 eV and that has a charge-doped-junction.
A three-junction tandem solar cell, comprising:
- a first cell comprising a Si substrate with a bandgap of about 1.1 eV and that has a charge-doped junction;
- a second cell on said first cell, said second cell comprising GaP that is isoelectronically co-doped with a deep acceptor element and a deep donor element to have an effective bandgap of about 1.55 eV and that has a charge-doped p-n junction;
- and
- a third cell on said second cell, said third cell comprising GaP that is isoelectronically co-doped with a deep acceptor element and a deep donor element to have an effective bandgap of about 2.05 eV and that has a charge-doped p-n junction.
A method of fabricating thin film GaP semiconductor material on a Si crystal lattice, comprising:
- depositing a thin film of GaP at a temperature of at least about 700° C. on the Si crystal lattice to achieve two-dimensional growth of polar GaP on non-polar Si;
- prior to cooling the thin film of GaP and the Si crystal lattice to room temperature, isoelectronically co-doping the thin film of GaP with a deep acceptor element and a deep donor element in a proportion that reduces compressive misfit strain of the GaP on the Si crystal lattice;
- and
- cooling the thin film of isoelectronically co-opted thin film of GaP and Si crystal lattice to room temperature as the misfit compressive strain reduces to a residual misfit strain of the isoelectronically co-doped GaP on the Si crystal lattice at room temperature that is of lesser magnitude than the compressive misfit strain of the GaP on the Si crystal lattice would be without such isoelectronic co-doping.
A method of modifying indirect bandgap GaP to act like a direct bandgap semiconductor material, comprising:
- isoelectronically co-doping GaP with N and Bi to form a GaP:N:Bi crystal lattice such that content of the N in the GaP:N:Bi crystal lattice is more than 3 at. % and content of the Bi in the GaP:N:Bi is more than 2 at. %.
A light-emitting diode, comprising:
- an active layer of GaP that is modified by isoelectronically co-doping the GaP with sufficient concentrations of N and Bi to comprise GaP:N:Bi with a lower effective bandgap in a range of about 1.55 eV to 1.93 eV, said active layer being sandwiched between:
- (i) a first barrier layer of GaP charged-doped to either n-type or p-type;
- and (ii) a second barrier layer of GaP charged-doped to either n-type or p-type, whichever is opposite the charge-doped first barrier layer.
A thermal voltaic cell, comprising:
- an InP substrate with a bandgap of about 1.45 eV;
- and
- a semiconductor cell deposited on the InP substrate, said semiconductor cell comprising InGaAs semiconductor alloy that is isoelectronically co-doped with N deep acceptor atoms and Bi deep donor atoms to provide an InGaAs:N:Bi crystal lattice.
A GaAs-based laser device, comprising:
- an active layer comprising GaAs that is isoelectronically co-doped with an isoelectronic atomic species that creates a deep acceptor in the GaAs and with an isoelectronic atomic species that creates a deep donor;
- and
- a bottom cladding layer and a top cladding layer sandwiching said active layer.
A laser diode, comprising:
- an active region comprising a set of AlzGa1-zP MQW layers that are isoelectronically co-doped with N and Bi to have AlzGa1-zP:N:Bi with lower effective bandgaps than AlzGa1-zP, said MQW layers being separated by barrier layers of AlzGa1-zP, said active region being sandwiched between a bottom SCH layer of GaP and a top SHC layer of GaP;
- a bottom cladding layer of group III-V semiconductor compound of alloy underlaying the bottom SCH layer;
- and
- a top cladding layer of Group III-V semiconductor compound or alloy overlaying the top SCH layer.
A photodiode, comprising:
- an active junction of Group III-V semiconductor compound or alloy comprising GaAs, which is modified to have a lower effective bandgap by isoelectronically co-doping the Group III-V semiconductor or alloy with sufficient concentrations of N and Bi to produce the lower effective bandgap, and which is fabricated on a substrate of Group III-V semiconductor compound or alloy.
A method of modifying a Group III-V semiconductor compound or alloy comprising Ga and As host atoms in a host crystal lattice to have a lower effective bandgap than the semiconductor compound or alloy has prior to modification, comprising:
- isoelectronically co-doping the semiconductor compound or alloy with a first isoelectronic dopant comprising atoms that form isoelectronic electron traps in the host crystal lattice that behave as deep acceptors and with a second isoelectronic dopant comprising dopant comprising atoms that form isoelectronic hole traps in the host crystal lattice that behave as deep donors.
A method of modifying a Group III-V semiconductor compound or alloy comprising In and P host atoms in a host crystal lattice to have a lower effective bandgap than the semiconductor compound or alloy has prior to modification, comprising:
- isoelectronically co-doping the semiconductor compound or alloy with a first isoelectronic dopant comprising atoms that form isoelectronic electron traps in the host crystal lattice that behave as deep acceptors and with a second isoelectronic dopant comprising atoms that form isoelectronic hole traps in the host crystal lattice that behave as deep donors.
A method of modifying a Group III-V semiconductor compound or alloy comprising Al, Ga and P host atoms in a host crystal lattice to have a lower effective bandgap than the semiconductor compound or alloy has prior to modification, comprising:
- isoelectronically co-doping the semiconductor compound or alloy with a first isoelectronic dopant comprising atoms that form isoelectronic electron traps in the host crystal lattice that behave as deep acceptors and with a second isoelectronic comprising dopant comprising atoms that form isoelectronic hole traps in the host crystal lattice that behave as deep donors.
A method of modifying a Group III-V semiconductor compound or alloy comprising In, Ga, and As host atoms in a host crystal lattice to have a lower effective bandgap than the semiconductor compound or alloy has prior to modification, comprising isoelectronically co-coping the semiconductor or alloy with a first isoelectronic dopant comprising atoms that form isoelectronic electron traps in the host crystal lattice that behave as deep acceptors and with a second isoelectronic dopant comprising atoms that form isoelectronic hole traps in the host crystal lattice that behave as deep donors.
A method of modifying a Group II-VI semiconductor compound or alloy comprising host atoms in a host crystal lattice to have a lower effective bandgap than the semiconductor compound or alloy has prior to modification, comprising isoelectronically co-doping the semiconductor or alloy with a first isoelectronic dopant comprising atoms that form isoelectronic electron traps in the host crystal lattice that behave as deep acceptors and with a second isoelectronic dopant comprising atoms that form isoelectronic hole traps in the host crystal lattice that behave as deep donors.
A semiconductor material for use as an active cell in a semiconductor device, comprising:
- a Group III-V semiconductor compound or alloy comprising Ga and As host atoms in a host crystal lattice that is isoelectronically co-doped with a first isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep acceptors, and with a second isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep donors.
A semiconductor material for use as an active cell in a semiconductor device, comprising a Group III-V semiconductor compound or alloy comprising In and P host atoms in a host crystal lattice that is isoelectronically co-doped with a first isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep acceptors, and with a second isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep donors, and which has an effective bandgap lower than InP.
A semiconductor material for use as an active cell in a semiconductor device, comprising a Group III-V semiconductor compound or alloy comprising Al, Ga and P host atoms in a host crystal lattice that is isoelectronically co-doped with a first isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep acceptors, and with a second isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep donors.
A semiconductor material for use as an active cell in a semiconductor device, comprising a Group III-V semiconductor compound or alloy comprising In, Ga and As host atoms in a host crystal lattice that is isoelectronically co-doped with a first isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep acceptors, and with a second isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep donors.
A semiconductor material for use as an active cell in a semiconductor device, comprising a Group II-VI semiconductor compound or alloy comprising host atoms in a host crystal lattice that is isoelectronically co-doped with a first isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep acceptors, and with a second isoelectronic dopant comprising atoms that form isoelectronic traps in the host crystal lattice that behave as deep donors.
A method of modifying indirect bandgap GaP to act like a direct bandgap semiconductor material, comprising:
- isoelectronically co-doping GaP with N and Bi to form a GaP:N:Bi crystal lattice such that content of the N in the GaP:N:Bi crystal lattice is more than 1 at. % and content of the Bi in the GaP:N:Bi is more than 1 at. %.
A light-emitting diode, comprising an active layer of Group III-V semiconductor compound or alloy comprising GaAs that is isoelectronically co-doped with N and Bi, said active layer being sandwiched between:
- (i) a first barrier layer of the Group III-V semiconductor compound or alloy charged-doped to either n-type of p-type;
- and (ii) a second barrier layer of the Group III-V semiconductor alloy charged-doped to either n-type or p-type, whichever is opposite the charge-doped first barrier layer.
A light-emitting diode, comprising an active layer of Group III-V semiconductor compound or alloy comprising:
- InP that is isoelectronically co-doped with a deep acceptor element and a deep donor element to have a lower effective bandgap than InP, said active layer being sandwiched between:
- (i) a first barrier layer of the Group III-V semiconductor compound or alloy charged-doped to either n-type of p-type;
- and (ii) a second barrier layer of the Group III-V semiconductor alloy charged-doped to either n-type or p-type, whichever is opposite the charge-doped first barrier layer.
A light-emitting diode, comprising an active layer of Group III-V semiconductor compound or alloy comprising:
- AlGaP that is isoelectronically co-doped with a deep acceptor element and a deep donor element, said active layer being sandwiched between:
- (i) a first barrier layer of the Group III-V semiconductor compound or alloy charged-doped to either n-type of p-type;
- and (ii) a second barrier layer of the Group III-V semiconductor alloy charged-doped to either n-type or p-type, whichever is opposite the charge-doped first barrier layer.
A light-emitting diode, comprising an active layer of Group III-V semiconductor compound or alloy comprising:
- InGaAs that is isoelectronically co-doped with a deep acceptor element and a deep donor element, said active layer being sandwiched between:
- (i) a first barrier layer of the Group III-V semiconductor compound or alloy charged-doped to either n-type or p-type;
- and (ii) a second barrier layer of the Group III-V semiconductor alloy charged-doped to either n-type or p-type, whichever is opposite the charge-doped first barrier layer.
A light-emitting diode, comprising an active layer of Group III-V semiconductor compound or alloy comprising:
- GaP that is isoelectronically co-doped with at least 1 at. % N and at least 1 at. % Bi, said active layer being sandwiched between:
- (i) a first barrier layer of the Group III-V semiconductor compound or alloy charged-doped to either n-type or p-type;
- and (ii) a second barrier layer of the Group III-V semiconductor alloy charged-doped to either n-type or p-type, whichever is opposite the charge-doped first barrier layer.
A photodiode, comprising:
- an active junction of Group III-V semiconductor compound or alloy comprising AlGaP, which is modified to have a lower effective bandgap by isoelectronically co-doping the Group III-V semiconductor or alloy with sufficient concentrations of N and Bi to produce the lower effective bandgap, and which is fabricated on a substrate of Group III-V semiconductor compound or alloy.
A photodiode, comprising:
- an active junction of Group III-V semiconductor compound or alloy comprising InGaAs, which is modified to have a lower effective bandgap by isoelectronically co-doping the Group III-V semiconductor or alloy with sufficient concentrations of N and Bi to produce the lower effective bandgap, and which is fabricated on a substrate of Group III-V semiconductor compound or alloy.
A photodiode, comprising:
- an active junction of Group III-V semiconductor compound or alloy comprising InP, which is modified to have a lower effective bandgap by isoelectronically co-doping the Group III-V semiconductor or alloy with sufficient concentrations of N and Bi to produce the lower effective bandgap, and which is fabricated on a substrate of Group III-V semiconductor compound or alloy.
A photodiode, comprising:
- an active junction of Group III-V semiconductor compound or alloy comprising GaP, which is modified to have a lower effective bandgap by isoelectronically co-doping the Group III-V semiconductor or alloy with at least 1 at. % N and at least 1 at. % Bi to produce the lower effective bandgap, and which is fabricated on a substrate of Group III-V semiconductor compound or alloy.
Dependencies are inferred from the claim text.