Electrochemical-based studies of Cu₂SnSe₃ nanocrystals and P3HT:PCBM for hybrid solar cells

In this work, we have fabricated hybrid heterojunction solar cells with structure ITO/ZnO/ P3HT:PCBM:CTSe NCs (optimized weight percentage 10 wt%)/MoO 3/Ag (device SM10). A thin layer of molybdenum oxide MoO₃ prepared by peroxomolybdic acid organosol as the precursor was used as hole transport layers (HTLs). The performance of the device was compared with ITO/ZnO/P3HT:PCBM:CTSe NCs/Ag(device S10). The important parameters such as global charge carrier mobility (μ), effective charge carriers lifetime (τ_n) and charge diffusion time (τ_d) have been extracted from electrochemical impedance spectroscopy (EIS) performed at the bias of 0.1 V in the dark. The Nyquist plot obtained from EIS has demonstrated effective carriers lifetime, global mobility and charge diffusion time for a device SM10 as 6.46 ms, 12.6 x 10^-4 cm² V^-1 S^-1 and 5.2 μs and for device S10 as 5.65 ms, 9.58 9 10^-4 cm² V^-1 S^-1 and 6.8 μs, respectively. (author)