Photoelectrical properties of photovoltaic structures based on CdTe/ZnO

The n-type ZnO layers were grown by ALD method on p-type CdTe substrate. I-V characteristics verified rectifying properties of the test ZnO/CdTe solar cell diode and exhibited photovoltaic effect when the junction was exposed to light. The series resistance of the diode, determined from the I-V curves, equals to 36 Ω. Such a high value is responsible for low value of fill factor and efficiency of the solar cell. Photoresponse properties of the studied junction were measured at room temperature. Efficient photoresponse was observed within wavelength range of 400-1000 nm. These results indicate that n-ZnO/p-CdTe junction is suitable for the fabrication of efficient solar cells. It was shown that the thickness of the ZnO layers can be also determined with the help of interference fringes of photoresponse analysis. Further work will involve a better understanding of the properties of window layer and junction formation processes.