Textured interfaces in monolithic perovskite/silicon tandem solar cells: advanced light management for improved efficiency and energy yield

Abstract

25.5% efficiency is demonstrated for monolithic perovskite/silicon tandem solar cell using textured foil and the impact of texture position on performance and energy yield is simulated.

Two‐Terminal Perovskites Tandem Solar Cells: Recent Advances and Perspectives

“…However, it also poses strict process compatibility and great challenges: 1) processing of the top‐cells without damage to the temperature‐sensitive bottom devices; 2) current‐matching between the two subcells for minimal power loss with use of appropriate recombination layers, since the overall current output is limited by the lower one; 3) optical management within the tandems due to their sensitivity to spectral variations in time or geographical location, which may impact the energy yield. The current records for two‐terminal devices are 25.5% for a perovskite–silicon tandem demonstrated by Jošt et al, 21.0% for a perovskite–perovskite tandem developed by Zhao et al, and 22.43% for a perovskite–CIGS tandem developed by Yang's group…”

“…Reflection losses are mainly attributed to the flat surface or refractive index mismatch of the multiple layers in tandem devices and significantly occur at surfaces of the front transparent electrode as well as the smooth Si bottom‐cell. Different light management strategies incorporating textured surfaces have been explored to improve the light trapping capability within the tandems, including back‐side textured device, back‐side textured device with the light management (LM) foil, both‐side textured device and fully flat device with an LM foil, as shown in Figure a. Schneider et al showed that the conformal deposition of a thin film perovskite solar cell directly onto the textured silicon cell reduced the reflection losses to 0.52 mA cm −2 .…”

“…However, it is challenging to deposit conformal, pinhole‐free perovskite layers with spin‐coating on such textured substrates in monolithic tandem devices. The most generally used strategy to reduce the reflection loss is incorporating a textured surface for the bottom‐cells, since the back‐side texture could enhance the photocurrent generation while not affecting the subsequent wet‐chemical processing of the perovskite cell …”

“…Figure shows the main perovskite‐based tandem experimental results published in the year 2015–2018. As can be seen, mechanically stacked perovskite–silicon tandems have currently achieved a high PCE of 27.1% based on Cs 0.15 (CH 5 N 2 ) 0.85 Pb(I 0.71 Br 0.29 ) 3 perovskite top subcell with a bandgap of 1.72 eV and crystalline silicon (c‐Si) bottom subcell, whereas monolithic perovskite–silicon tandems have approached 25.5% efficiency. The perovskite–perovskite tandems have achieved a four‐terminal efficiency of 23.1% by utilizing FA 0.8 Cs 0.2 Pb(I 0.7 Br 0.3 ) 3 ( E g = 1.75 eV) and (FASnI 3 ) 0.6 (MAPbI 3 ) 0.4 ( E g = 1.25 eV), with a monolithic tandem efficiency of 21.0% .…”

“…Efficiency record evolution of two‐terminal perovskite–silicon, perovskite–perovskite, and perovskite–CIGS tandem devices, as well as four‐terminal perovskite–silicon, perovskite–perovskite and perovskite–CIGS tandems, according to the online publication date.…”