Study of ultra-thin CdTe/CdS heterostructure solar cell purveying open-circuit voltage ∼1.2 V

Abstract

This study focuses on aiming higher stabilized sunlight to electricity conversion efficiency for Cadmium Telluride (CdTe) absorber based solar cell. Common CdTe solar cell with Au back or Zinc Telluride (ZnTe) back surface field (BSF) with Cu back metal has voltages < 1V. The reason behind this low voltage has been investigated in details. In this report, simulation yielding of (M = Cu, Ni, Au, Ir, Pd, and Pt) thin-film solar cell (TFSC) has been presented. The solar cell has been modelled and analyzed using Analysis of Microelectronic and Photonic Structures – 1 Dimensional (AMPS-1D) device simulator for various back metals with work function, Φm ≥ 5 eV. The thickness was varied from 100–1800 nm, and from 15–100 nm for the active p-CdTe absorber, and n-Cadmium Sulphide (CdS) window layers, respectively, to optimize the device depth. Meanwhile, the donor and acceptor concentration was varied to outline their effects on photovoltaic (PV) parameters. The utmost efficiency (η) of ∼30% along with open circuit voltage of 1.194 V, short circuit current density of 28.6 mA cm−2, and fill factor (FF) of 89.3% has been achieved ideally with Platinum (Pt) back contact at (111) plane under standard test conditions (STC) of and 1 Sun illumination (1000 W m−2) at air mass (AM) 1.5. Lastly, the cell operating temperature was varied from to to verify the thermal stability of the proposed structure. Present work provides a guideline to select back metal in CdTe solar cell. Our proposed solar cell offers the prospect of being a highly efficient cost effective second generation (2G) TFSC.