Efficient Semitransparent Solar Cells Enabled by Introducing N-Ethylbenzylamine Additives into Thin Layer of Halide Perovskites

Semitransparent perovskite solar cells (ST-PSCs) have opened up new applications in tandem devices and building-integrated photovoltaics. Decreasing the thickness of the perovskite film makes it feasible to fabricate semitransparent perovskite layers. However, the formation of high-quality thin perovskite films has been a challenge during the film manufacturing process since the crystallization dynamics of thinner (<200 nm) films are different from that of thick films. In this article, we demonstrate a feasible method to fabricate a thinner layer of highly crystalline perovskites with low defect density for efficient ST-PSCs by introducing N-Ethylbenzylamine (EBA) to modify halide perovskites through Lewis acid-base interaction. As a result, a semitransparent solar cell based on EBA-treated perovskite with a film thickness of only ∼190 nm exhibits a high power conversion efficiency (PCE) of 14.77%, an average visible transmittance (AVT) of 13.2%, and an excellent light utilization efficiency (LUE) of 1.95%, which is the highest value in the ST-PSCs with Au as the electrode. Our findings highlight the effectiveness of the EBA additive in improving the photovoltaic performance of ST-PSCs, offering valuable insights into developing efficient and transparent photovoltaic technologies.