High efficient hybrid bulk hetero junction thin-film solar cell embedded with kesterite Cu2ZnSnS4 quantum dots

Abstract

The photovoltaic performance of kesterite Cu 2 ZnSnS 4 (CZTS) quantum dot (QD) incorporated poly(3-hexylthiophene-2,5-diyl) (Alvarado et al., 1998; Alvarado et al., 1998) [6,6]: phenyl-C61butyric acid hexyl ester (P3HT:PCBH) polymer matrix based organic hybrid heterojunction solar cell configuration is investigated. The inorganic filler material CZTS QDs with P3HT:PCBH matrix, forms double bulk hetero junction (BHJ) throughout in the active layer, which facilitates rapid exciton dissocitaion process at P3HT:PCBH and CZTS:PCBH interfaces that results effective charge carrier separation. The prepared active layer material has been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), Raman and fourier transform infra red (FTIR). The enhanced optical absorbance of prepared hybrid structure has been verified by UV–Visible analysis. It has been observed that the improvement in photo conversion efficiency (PCE) from 2.36% for the solar cell device P3HT:PCBH to 4.12% for CZTS QD based P3HT:PCBH hybrid organic solar cell device. This dramtaic increase in PCE, is mainly due to the significant enhancement in short-circuit current density (J sc ) from 7.6 mA/cm 2 to 11.2 mA/cm 2 . That suggests, the incorporation of p-type kesterite CZTS QDs into P3HT:PCBH polymer matrix enhances the effective exciton dissociation at interfaces resulting charge separation and their fast extraction to electrodes inhibiting e − /h + pair recombination. Furthermore, the hybrid solar cell shows remarkable time stability retaining 80% of original PCE measured after 30 days under ambient environment conditions. The hybrid organic solar cell device shows thermal stability by retaining 95.6% of its intial efficiency measured which has been tested in the temperature range 20–80 °C. • Photovoltaic performance of CZTS QDs:P3HT:PCBH hybrid thin film solar cell is investigated. • PCE of hybrid device has been observed to enhance from 2.36% to 4.12%. • It shows time and thermal stability retaining 80% and 95.6% efficiency.