Chemically deposited thin films of PbSe as an absorber component in solar cell structures

PbSe thin films were prepared by chemical deposition using dimethylselenourea as a source of selenide ions. Depending on the duration (30 min to 4 h) and temperature (30–60 °C) of the deposition, and the substrate, the films show a high degree of preferred orientation for the (111) planes. The texture coefficients could be up to 5 for these planes. The crystallite diameters are in the 30–35 nm range, and optical bad gap, 0.4–0.7 eV. The electrical conductivity is p-type, 0.01–10 (Ω cm)− 1. These films were deposited over CdS/Sb2S3 or CdS/Sb2Se3 solar cell structures as an additional absorber. In a CdS/Sb2Se3/PbSe cell, this addition increases the short circuit current density (Jsc) from 0.2 mA/cm2 to 8.9 mA/cm2 and conversion efficiency (η) from 0.04% to 0.99%. In a CdS/Sb2S3/PbSe cell, Jsc is 5.91 mA/cm2; η, 0.98%; and open circuit voltage, 560 mV.