Regulation of Interfacial Charge Transfer and Recombination for Efficient Planar Perovskite Solar Cells

Abstract

Control of dynamics at the electron transport layer–perovskite interface, such as charge transfer and recombination, is essential in achieving high‐efficiency planar perovskite solar cells (PSCs). Herein, it was observed that the trade‐off between unfavorable electron transport of a thick SnO2 film and serious electron recombination at thin SnO2 film/perovskite interfaces is essential for the performance of SnO2‐based planar PSCs. The optimized efficiency of devices beyond 20% is obtained by using a two‐step deposition of SnO2. Moreover, trap‐assisted carrier recombination is significantly suppressed by using the diethylenetriaminepentaacetic acid passivator via the formation of coordination with undercoordinated Sn and Pb2+ ions. As a result, the champion device demonstrates a promising efficiency of 21.28% with negligible hysteresis and much improved environmental stability, i.e., retaining 98% of the initial efficiency under ambient atmosphere over 1000 h.

Advanced partial nucleation for single-phase FA0.92MA0.08PbI3-based high-efficiency perovskite solar cells

“…8d. The Tra-FA 0.9 MA 0.1 -based device showed a considerable drop, reflecting more facile decomposition of the absorber layer, due possibly to the presence of defects [53][54][55]. In the MCP-FA 0.92 MA 0.08based device, the stability curve remained linear with little slope throughout the observed period, which supports the notion of reduced defects, as indicated by the TRPL, PL, and EIS results discussed above.…”

Template‐Assisted Formation of High‐Quality α‐Phase HC(NH2)2PbI3 Perovskite Solar Cells

“…The residual PbI 2 affects the quality of the film morphology and restricts the formation of phase‐pure FAPbI 3 . The FAI‐30 film shows a smooth and flattened morphology in which grain size increases to up to ≈500 nm in size . As a control, C‐FAPbI 3 has a rough surface with poor cross‐sectional properties (Figure S12, Supporting Information).…”

Tin Oxide Electron‐Selective Layers for Efficient, Stable, and Scalable Perovskite Solar Cells

“…[84][85][86] Furthermore, SnO 2 possesses a relatively low refractive index (n) of ≤2 (at 550 nm). [87][88][89] Consequently, if SnO 2 is deposited on fluorine-doped tin oxide (FTO) or indium-doped tin oxide (ITO) coated glass, the transmittance of SnO 2 /transparent conductive oxide (TCO) stack can be improved (in comparison to neat FTO or ITO) thanks to proper refractive-index matching. [36,90] On the device level, this also enables a better optical match with the layers between which it is sandwiched, i.e., the glass/TCO stack [91] and the perovskite, in case of n-i-p PSCs, resulting in lower reflective losses.…”