Determination of Carrier Lifetimes in Organic-Inorganic Hybrid Solar Cells Based on Sb2S3 by Using the Time-Resolved Photocurrent

This paper presents organic-inorganic hybrid solar cells (SCs) based on ZnO/Sb2S3/P3HT heterojunctions. The ZnO and the Sb2S3 layers were grown using atomic layer deposition (ALD). Although four cells were fabricated on one substrate by using the same process, their open-circuit voltages (V (OC) ) and short-circuit current densities (J (SC) ) were different. The SC with a high V (OC) has a low J (SC) . The causes of the changes in the V (OC) and the JSC were investigated by using photoluminescence (PL) spectroscopy and optically-biased time-resolved photocurrent (TRPC) measurements. The PL results at 300 K showed that the emission positions of the Sb2S3 layers in all cells were similar at approximately 1.71 eV. The carrier lifetime of the SCs was calculated from the TRPC results. The lifetime of cell 4 with the highest J (SC) decreased drastically with increasing intensity of the continuous-wave optical bias beam. Therefore, the defect states in the ZnO layer contribute to the J (SC) , but degrade the V (OC) .