Controlling the performance of photovoltaic cell based on nanostructured Cd_1−xZn_xTe semiconductors

Abstract

Generally, cadmium zinc telluride Cd_1−x Zn _x Te nanopowders (x = 0.0, 0.2, 0.5, 0.8 and 1.0) have been purposefully tailored using a facile chemical method based on inexpensive hydroxides precursor compounds. Typically, the hydroxides were obtained from the salts solutions using ammonia solution as a base at stable pH 9. Then, a suitable amount of sodium borohydride (NaBH₄) solution was inserted to reduce the hydroxide precursors to form the metalloid alloy. The impact of Zn²⁺ ion content on the crystal structure and microstructure of cadmium telluride (CdTe) has been recognized using powder X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) measurements. Evidently, the annealed metalloid alloy Cd_1−x Zn _x Te samples at a temperature of 300 °C for 3 h revealed a cubic crystal structure. The morphologies of the prepared samples were very fluffy like the clouds and the average diameter was between 1.0 and 2.5 μm. The optical properties of the samples were determined using UV-vis-near IR spectrophotometer. In this regards, Zn²⁺ ion replaced CdTe at different molar ratios was found to increase the band gap energy. Finally, the highest photovoltaic response was achieved by a power conversion efficiency per unit area of 7.2% and a filling factor (FF) 44.79% for Cd_0.8Zn_0.2Te composition.

Keywords:

• Cadmium zinc telluride
• optical properties
• photoelectrochemical properties

Acknowledgment

The authors acknowledge Prof Dr Lee Chow, Department of Physics, University of Central Florida, Orlando, Florida 32816, USA for his reviewing this manuscript.