Demonstration of homojunction ZnTe solar cells

We report on the proof of photovoltaic activity of homojunction ZnTe solar cells in which n-ZnTe layers are fabricated by thermal diffusion of Al into p-ZnTe at several diffusion times to control the junction depth. An open circuit voltage of approximately 0.9 V was obtained under 1× sun AM1.5G condition in all solar cells, independent of diffusion times, while a short circuit current dropped down with increasing the diffusion time due to an increased light absorption in heavily defective Al-diffused layer. These fundamental results provide a basis for future development of intermediate band solar cells based on ZnTe materials. © 2010 American Institute of Physics.