Featuring and combining of ZnSe buffer thickness and Mo back contact for enhanced CdTe solar cell performance

Cadmium telluride (CdTe) has potential for solar cell applications and has unique properties such as a high absorption coefficient, economic, better power conversion efficiency, and better stability. However, variations in transmittance, lower p-type conductivity, and recombination loss due to interface defects. This research intends to overcome and enrich the opto-electrical properties of CdTe featuring a 40–70 nm (with 10 nm interval) Zinc selenide (ZnSe) buffer layer and a constant layer thickness of molybdenum (Mo) back contact through the thermal evaporation technique. The effect of ZnSe layer thickness on opto-electrical properties of CdTe cell layers is investigated, and at the optimal ZnSe thickness of 70 nm, XRD analysis reveals a significant improvement in crystallinity and grain growth, with a grain size of 48 nm. Additionally, electrical conductivity reaches 7.5 × 10^–3 S/cm, and transmittance increases to 72%. The optical band gap, derived from the Tauc plot, is determined to be 2.65 eV. Moreover, the current–voltage (J-V) curve at this thickness shows a V_oc of 0.82 V, a Jsc of 27.3 mA/cm², and a power conversion efficiency (PCE) of 19%, indicating notable enhancements in the solar cell’s overall functional performance.