Properties of Pulsed Laser Deposited CdS_xTe_1-x Films on Glass

Abstract

Interdiffusion of sulfur and tellurium across the CdS/CdTe interface is fundamentally important in the operation of CdTe solar cells. However, the properties of the resulting alloy semiconductor, CdSxTe1-x, are not well understood. We have prepared films of this ternary material by pulsed excimer laser deposition (PLD) across the alloy range. These films were examined by x-ray diffraction, wavelength dispersive x-ray spectroscopy, optical absorption, and Raman scattering to determine the influence of sulfur content on the crystal structure, lattice constant, energy gap, and vibrational mode behavior.

A comparative study of microstructural stability and sulphur diffusion in CdS/CdTe photovoltaic devices

“…The spectra illustrate the expected red-shift of optical properties [32,49] due to sulphur alloying with CdTe. The wavelength window chosen for Fig.…”

Properties of CdS/sub x/Te/sub 1-x/ alloy films [in solar cells]

“…Figure 5 shows a sequence of PL spectra obtained at 10 K from four alloy films (CST-10, 6,7, and 9) with sulfur concentrations, respectively, of 0.01 7, 0.03, 0.057, and 0.1 1. As expected from the known band gap "bowing" [8,9], the near-band-edge peak decreases in phloton energy below the position for pure CdTe as the S We have also obtained PL from the CdS/CdTe interface region of our rf sputtered cells. In order to minimize PL from the soda-lime glass, SnO,, and the S-rich region, we used excitation with a HeNe laser at 632.8 nm.…”