Device simulation of quasi-two-dimensional perovskite/silicon tandem solar cells towards 30%-efficiency

Abstract

Perovskite/silicon (Si) tandem solar cells have been recognized as the next-generation photovoltaic technology with efficiency over 30% and low cost. However, the intrinsic instability of traditional three-dimensional (3D) hybrid perovskite seriously hinders the lifetimes of tandem devices. In this work, the quasi-two-dimensional (2D) (BA)2(MA) n – 1Pb n I3n + 1 (n = 1, 2, 3, 4, 5) (where MA denotes methylammonium and BA represents butylammonium), with senior stability and wider bandgap, are first used as an absorber of semitransparent top perovskite solar cells (PSCs) to construct a four-terminal (4T) tandem devices with a bottom Si-heterojunction cell. The device model is established by Silvaco Atlas based on experimental parameters. Simulation results show that in the optimized tandem device, the top cell (n = 4) obtains a power conversion efficiency (PCE) of 17.39% and the Si bottom cell shows a PCE of 11.44%, thus an overall PCE of 28.83%. Furthermore, by introducing a 90-nm lithium fluoride (LiF) anti-reflection layer to reduce the surface reflection loss, the current density (J sc) of the top cell is enhanced from 15.56 mA/cm2 to 17.09 mA/cm2, the corresponding PCE reaches 19.05%, and the tandem PCE increases to 30.58%. Simultaneously, in the cases of n = 3, 4, and 5, all the tandem PCEs exceed the limiting theoretical efficiency of Si cells. Therefore, the 4T quasi-2D perovskite/Si devices provide a more cost-effective tandem strategy and long-term stability solutions.

Top cell design and optimization of all-chalcopyrite CuGaSe₂/CuInSe₂ two-terminal tandem solar cells

“…叠层太阳能电池 是由两个或多个太阳能电池串联组成 [18] , 可以吸 收不同能量的光子, 从而提高太阳能电池的PCE. 在叠层器件中, 对不同带隙太阳能电池进行串联, 使其带隙互补, 宽带隙吸收层捕获高能光子以提供 高开路电压并减少热化损失, 窄带隙吸收层捕获低 能量光子以扩大光响应 [19,20] , 其中被广泛采用的器 件构型为4端(4T)机械堆叠串联和2T单片串联 [21] . 虽然在4T叠层太阳能电池中, 子电池易于制作, 但是其使用的三层透明导电氧化物(TCO)材料会 导致严重的光寄生损失以及两个独立电路会产生 较高的成本 [22] , 因此, 2T单片叠层太阳能电池更 有研究价值.…”