First Demonstration of Top Contact-Free Perovskite/Silicon Two-Terminal Tandem Solar Cells for Overcoming the Current Density Hurdle

Current density plays a substantial role in monolithic tandem solar cells; however, it is difficult to control because subcells and auxiliary layers are stacked and serially connected vertically to obtain higher voltages. The vertically stacked structure intrinsically triggers inevitable parasitic absorption. In current typical perovskite/silicon two-terminal (2-T) tandem solar cells, 5-10 layers are placed on the light path, even though they are not current generating layers. These layers usually include transparent window layers, buffer layers, carrier extraction layers, and recombination layers. Therefore, the development of top contact-free architectures to reduce parasitic absorption in 2-T tandem solar cells is required for achieving high efficiency. In this study, a top contact-free perovskite/silicon 2-T tandem solar cell with quasi-interdigitated intermediate electrodes (Q-IDIEs) is reported for the first time. Several layers placed above the perovskite layer in conventional devices are relocated to the backside of the perovskite. The Q-IDIE, composed of a patterned Ni/NiOX shell above the full-deposited TiO2, was fabricated by the following processes: photolithography, lift-off, and oxidation. The device results in 4.23% efficiency with an open-circuit voltage of 1.54 V. This tandem architecture is expected to be a breakthrough for overcoming the theoretical efficiency limit of single-junction solar cells with further optimization.

Dowon Pyun and Sang Won Lee and Youngwoong Kim and Gyeong Sun Jang and Dongjin Choi and Seok Hyun Jeong and Hoyoung Song and Solhee Lee and Sujin Cho and Jiryang Kim and Dongkyun Kang and Ha Eun Lee and Ji Yeon Hyun and Changhyun Lee and Hyun Jung Park and Jae Keun Hwang and Wonkyu Lee and Nam Joong Jeon and Jangwon Seo and Yoonmook Kang and Donghwan Kim and Hae Seok Lee

ACS Applied Energy Materials

Ni oxidation,honeycomb-shaped,parasitic absorption,quasi-interdigitated intermediate electrode,tandem solar cells,top contact-free

2023

3

10.1021/ACSAEM.2C02649/SUPPL_FILE/AE2C02649_SI_001.PDF

25740962

5

2687-2697

American Chemical Society

6