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/Sb 2 S 3 /P 3 HT heterojunctions. The ZnO and the Sb 2 S 3 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 Sb 2 S 3 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 .