TiO₂/SnO₂ electron transport double layers with ultrathin SnO₂ for efficient planar perovskite solar cells

Abstract

The electron transport layer (ETL) plays an important role on the performance and stability of perovskite solar cells (PSCs). Developing double ETL is a promising strategy to take the advantages of different ETL materials and avoid their drawbacks. Here, an ultrathin SnO2 layer of ~ 5 nm deposited by atomic layer deposit (ALD) was used to construct a TiO2/SnO2 double ETL, improving the power conversion efficiency (PCE) from 18.02% to 21.13%. The ultrathin SnO2 layer enhances the electrical conductivity of the double layer ETLs and improves band alignment at the ETL/perovskite interface, promoting charge extraction and transfer. The ultrathin SnO2 layer also passivates the ETL/perovskite interface, suppressing nonradiative recombination. The double ETL achieves outstanding stability compared with PSCs with TiO2 only ETL. The PSCs with double ETL retains 85% of its initial PCE after 900 hours illumination. Our work demonstrates the prospects of using ultrathin metal oxide to construct double ETL for high-performance PSCs.

Homogenizing the Electron Extraction via Eliminating Low‐Conductive Contacts Enables Efficient Perovskite Solar Cells with Reduced Up‐Scaling Losses

“…Figure 1g shows that the conductivity of TiO 2 /SnO 2 is higher than that of TiO 2 , which agrees with the previous reports. [26,40] Moreover, the conductivity of TiO 2 /SnO 2 has further been increased with the incorporation of AH, which can be attributed to the enhanced contact between SnO 2 and TiO 2 .…”

The impact of moisture on the stability and degradation of perovskites in solar cells

“…Notably, perovskite solar cells with the CQD-SnO 2 ETL retained over 84% of their initial PCE after 1000 hours of continuous irradiation under 1-sun illumination, effectively suppressing perovskite degradation from the bottom contact. Moreover, utilizing a TiO 2 /SnO 2 double ETL 192 and surface modification of ZnO by anchoring fullerene material, 193 and interlayer modifiers between oxide ETLs and perovskite can improve stability in PSCs. 194…”

Design and Device Numerical Analysis of Lead-Free Cs2AgBiBr6 Double Perovskite Solar Cell

“…For instance, the influence of double TiO 2 /PFN ETL on the performance of organic P3HT:PC 61 BM-based solar cells was investigated and it was found that the PCE increases up to 2.5 times compared to that of single ETL cells [56]. Further, a double TiO 2 /SnO 2 ETL was employed resulting in a PCE improvement from 18.02% to 21.13% for a lead-based PSC [57]. Double Nb 2 O 5 /ZnO ETL was also applied in lead-based PSCs, resulting in a high device performance in terms of efficiency and stability thanks to the energy band matching between the ETLs and the absorber and the ITO contact [58].…”