Balancing Charge‐Carrier Transport and Recombination for Perovskite/TOPCon Tandem Solar Cells with Double‐Textured Structures

Abstract

The ongoing success of tunnel oxide passivating contact (TOPCon) solar cells in the photovoltaic community in conjunction with the continuous advancements in the fabrication technologies of perovskite‐based tandem devices make it possible to access highly‐efficient perovskite/TOPCon tandem solar cells (TSCs). However, the development of such tandem solar cells is still in its infancy. One of the main challenges facing these devices is the balance of passivation and contact properties, especially on the textured crystalline silicon substrates. This article focuses on the double‐textured TOPCon structures, and systematically investigates their passivation and contact properties with the purpose of balancing charge‐carrier recombination and transport properties. The experiment results show that passivation and contact properties of the double‐textured TOPCon structures can be well‐regulated by means of rearranging the schedules of annealing processes and radio frequency powers of SiOx deposition. The mechanisms of charge‐carrier transport on the textured structures are closely studied, suggesting that charge carriers prefer to transport via the valleys of pyramids where the SiOx layer is thin or missing. As a result, the proof‐of‐concept perovskite/TOPCon TSCs featuring the double‐textured structures are successfully fabricated with a remarkable efficiency of 28.49%.

Device Physics and Design Principles of Mixed‐Dimensional Heterojunction Perovskite Solar Cells

“…underneath the c-Si surface serves as polar dopants to form a high/low junction between c-Si substrates, offering an assisted electric field to suppress minority carrier recombination and accelerate majority carrier extraction. [9] Inspired by the ingenious designs of c-Si devices, researchers have attempted various strategies for PSCs, including homojunction, heterojunction, bandgap-gradient, mixed-dimensional perovskite, etc. [10][11][12][13] Among these advanced designs, mixed-dimensional perovskite, such as 2D/3D perovskite, has become a research hotspot due to its unique advantages of high compatibility in the fabrication process and high-efficiency potential.…”

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

“…Figure S1 and Table S1 represent the homojunction-based tandem solar cells reported from 2015. Although the number of reported cases was lower than that of SHJ-based tandem solar cells, a gradual increase was observed in the number of publications recently. − In homojunction-based tandem solar cells, TCO materials such as ITO and IZO have been widely employed as recombination layers. − , In addition to the two aforementioned disadvantages of TCO, an additional TCO deposition process is required, which leads to high fabrication costs. Hence, the development of perovskite/TOPCon tandem solar cells with a TCO-free recombination layer is necessary.…”

Morphology of an ITO recombination layer deposited on a silicon wire texture for potential silicon/perovskite tandem solar cell applications

“…The obtained wires structure plays a double role: 1) reduction of solar radiation reflection in the wavelength range of 300-1200 nm to an effective value below 5% and 2) scaffolding for the perovskite layer in silicon/perovskite tandem cells. In the subject of tandem solar cells, methods of depositing a perovskite absorber on a classically textured silicon surface, mainly in the form of pyramids, have already been described [13][14][15][16] even on the industrial-size Si solar cells [17].…”