Perovskite solar cells (PSCs) have attracted remarkable attention from the photovoltaic research community due to their excellent optoelectronic properties and ease of fabrication. The power conversion efficiency (PCE) increased from 3% to above 20% in a short span of one decade. Typically, PSCs consist of a perovskite layer as an active medium, which is sandwiched between the electron transport layer (ETL) and hole transport layer (HTL). The photo-generated charge carriers are extracted to the external circuit with the help of transparent conducting oxide (TCO) layer and metal contact on the opposite sides of the stack. Most of the high efficient PSC consist of spiro-OMeTAD, doped with LiTFSI as HTL. However, degradation of spiro-OMeTAD beyond 80 °C and hydrophilic LiTFSI being the root cause of moisture-induced degradation have led to the exploration of an alternative HTL. The present work involves the venture of finding novel HTL using an inexpensive route.

In this talk, the advantage of organic inorganic metal halide perovskite as an absorbing layer in a solar cell and the relevant challenges will be introduced in the beginning. Thereafter, the fabrication of PSCs using the spiro-OMeTAD as a standard HTL will be presented to set up the benchmark. Subsequently, replacement of the spiro-OMeTAD by a novel indigenously made HTL (synthesized in the Chemistry Department at IIT Madras), referred to as HTM-2 hereafter, will be discussed. Finally, the device performance of PSC using HTM-2 as HTL will be compared with the PSC incorporating standard spiro-OMeTAD in this presentation.