Titanium Silicide: A Promising Candidate of Recombination Layer for Perovskite/Tunnel Oxide Passivated Contact Silicon Two-Terminal Tandem Solar Cells

• Published in: ACS applied materials & interfaces Vol. 16; no. 22; pp. 28379 - 28390
• Main Authors: Pyun, Dowon, Choi, Dongjin, Bae, Soohyun, Lee, Sang-Won, Song, Hoyoung, Jeong, Seok Hyun, Lee, Solhee, Hwang, Jae-Keun, Cho, Sujin, Lee, Huiyeon, Woo, Myeongji, Lee, Yerin, Kim, Kyunghwan, Kim, Youngmin, Lee, Changhyun, Choe, Youngho, Kang, Yoonmook, Kim, Donghwan, Lee, Hae-Seok
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 05.06.2024
• Subjects: electron transfer; Energy, Environmental, and Catalysis Applications; reflectance; silicon; titanium; oxidation; recombination layer; perovskite/TOPCon tandem solar cells; TCO-free; titanium silicide
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.4c01864

This study proposes a titanium silicide (TiSi2) recombination layer for perovskite/tunnel oxide passivated contact (TOPCon) 2-T tandem solar cells as an alternative to conventional transparent conductive oxide (TCO)-based recombination layers. TiSi2 was formed while TiO2 was made by oxidizing a Ti film deposited on the p+-Si layer. The reaction formation mechanism was proposed based on the diffusion theory supported by experimental results. The optical and electrical properties of the TiSi2 layer were optimized by controlling the initial Ti thicknesses (5–100 nm). With the initial Ti of 50 nm, the lowest reflectance and highly ohmic contact between the TiO2 and p+-Si layers with a contact resistivity of 161.48 mΩ·cm2 were obtained. In contrast, the TCO interlayer shows Schottky behavior with much higher contact resistivities. As the recombination layer of TiSi2 and the electron transport layer of TiO2 are formed simultaneously, the process steps become simpler. Finally, the MAPbI3/TOPCon tandem device yielded an efficiency of 16.23%, marking the first reported efficiency for a device including a silicide-based interlayer.