Photovoltaic devices including heterojunctions
View Patent ↗A photovoltaic cell can include a heterojunction between semiconductor layers. The first semiconductor layer can include a III-V compound semiconductor, the first semiconductor layer positioned over a transparent conductive layer. A second semiconductor layer can include a II-VI compound semiconductor, the second semiconductor layer positioned between the first semiconductor layer and a back metal contact.
1. A photovoltaic device comprising:
a transparent conductive layer on a substrate;
a first semiconductor layer including an n-type III-V compound semiconductor, the first semiconductor layer positioned over the transparent conductive layer;
a second semiconductor layer including a p-type II-VI compound semiconductor, the second semiconductor layer positioned between the first semiconductor layer and a back metal contact, wherein a rectifying heterojunction is formed between the III-V and II-VI compound semiconductors; and
an interfacial layer between the first semiconductor layer and the second semiconductor layer that enhances the rectifying heterojunction between the III-V and II-VI compound semiconductors, wherein the interfacial layer includes cadmium zinc oxide.
2. The device of claim 1 , wherein the II-VI compound is a cadmium telluride.
3. The device of claim 1 , wherein the III-V compound is a gallium nitride.
4. The device of claim 3 , wherein the gallium nitride is a gallium aluminum nitride.
5. The device of claim 1 , wherein the first semiconductor layer is a window layer of the device and the second semiconductor layer is an absorber layer of the device.
6. A system for generating electrical energy comprising:
a multilayered photovoltaic cell including:
a transparent conductive layer on a substrate,
a first semiconductor layer including an n-type III-V compound semiconductor, the first semiconductor layer positioned over the transparent conductive layer,
a second semiconductor layer including a p-type II-VI compound semiconductor, the second semiconductor layer positioned between the first semiconductor layer and a back metal electrode, wherein a rectifying heterojunction is formed between the III-V and II-VI compound semiconductors, and
an interfacial layer that enhances the rectifying heterojunction between the III-V and II-VI compound semiconductors, wherein the interfacial layer includes cadmium zinc oxide;
a first electrical connection connected to the transparent conductive layer; and
a second electrical connection connected to the back metal electrode, the back metal electrode being adjacent to the second semiconductor layer.
7. The system of claim 6 , wherein the II-VI compound is a cadmium telluride and the III-V compound is a gallium nitride.
8. The system of claim 6 , wherein the first semiconductor layer is a window layer of the device and the second semiconductor layer is an absorber layer of the device.