Cost-effective thiophene-assisted novel dopant-free hole transport materials for efficient perovskite solar cell performance

Abstract

Hole transport material (HTM)-assisted halide perovskite solar cells (PSCs) have demonstrated excellent performances in photovoltaic technology within a short period of time. Herein, cost-effective hole transport materials (HTMs), namely BTBDT and BTDTP, were successfully synthesized using thiophene, and engineered into perovskite devices, exhibiting a higher photovoltaic performance than that of the commercially available Spiro-OMeTAD. The PSCs with BTBDT and BTDTP HTMs exhibited a power conversion efficiency (PCE) of 16.96% and 17.60%, respectively. Under the exact conditions, the test device employing Spiro-OMeTAD demonstrated a PCE of 13.16%. The champion short-circuit density of 25.73 mA cm⁻² was achieved in the present study for the BTDTP-assisted PSC. Furthermore, the device stability was examined after 60 days, demonstrating a PCE of 16.08% for BTDTP, which was much more stable than the Spiro-OMeTAD device (5.89%). Besides the unique device performance, the significant features such as simple synthetic process, dopant-free conditions and cost effectiveness of BTBDT and BTDTP make them plausible alternatives to Spiro-OMeTAD as the hole transport material in PSCs.