Work

Improved interface passivation in high-efficiency Se-alloyed CdTe solar cells using a SnO2/ZnO n-type bilayer

Year: 2025

Type: article

Abstract: Thin film cadmium telluride is the most important second-generation solar cell technology. Although the photo-absorber is polycrystalline, high conversion efficiency has been achieved by effectively passivating the grain boundaries and other bulk defects. In this paper, we report on the use of a bilayer SnO 2 /ZnO n-type buffer to improve passivation at the p–n junction interface to achieve 21.7% efficiency. We have assessed the quality of the interface with highly sensitive electrical measurements and a combination of high-resolution electron microscopy and cathodoluminescence. High-resolution cathodoluminescence has enabled the measurement of the recombination velocity to quantify the improvement in interface defect passivation. We have combined this with direct observation of the coherence of the interface at the atomic scale. The use of these techniques will revolutionize our ability to assess future passivation strategies at the front p–n junction and also at the back contact of thin film photovoltaic devices.

Source: Solar Energy Materials and Solar Cells

DOI: 10.1016/j.solmat.2025.114139