Highly stable and efficient all-inorganic lead-free perovskite solar cells with native-oxide passivation

Abstract

There has been an urgent need to eliminate toxic lead from the prevailing halide perovskite solar cells (PSCs), but the current lead-free PSCs are still plagued with the critical issues of low efficiency and poor stability. This is primarily due to their inadequate photovoltaic properties and chemical stability. Herein we demonstrate the use of the lead-free, all-inorganic cesium tin-germanium triiodide (CsSn0.5Ge0.5I3) solid-solution perovskite as the light absorber in PSCs, delivering promising efficiency of up to 7.11%. More importantly, these PSCs show very high stability, with less than 10% decay in efficiency after 500 h of continuous operation in N2 atmosphere under one-sun illumination. The key to this striking performance of these PSCs is the formation of a full-coverage, stable native-oxide layer, which fully encapsulates and passivates the perovskite surfaces. The native-oxide passivation approach reported here represents an alternate avenue for boosting the efficiency and stability of lead-free PSCs.

Efficient and Stable FASnI3 Perovskite Solar Cells with Effective Interface Modulation by Low‐Dimensional Perovskite Layer

“…[51][52][53] In this work, the device stabilityi se valuated with al ight-soakingt est in ambient air under continuous simulated solar AM 1.5 Gi llumination, resulting in as teady sample temperatureo fa pproximately 50 8C ( Figure 7b). Considerable efforts have been made to improve the devices tabilityo ft in and lead-free PSCs.…”

“…[1] However, the toxicity of lead is deemeda sacritical concern for their commercialization in the future. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Amongt he different lead-free perovskites reported to date, tin halide PSCs have the highest conversion efficiency of 9.6 %, [16] which meanst hey are one of the most promising candidates to substitutePbowing to their similarionic structure. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Amongt he different lead-free perovskites reported to date, tin halide PSCs have the highest conversion efficiency of 9.6 %, [16] which meanst hey are one of the most promising candidates to substitutePbowing to their similarionic structure.…”

Halide Perovskite Nanocrystals for Next‐Generation Optoelectronics

“…Surface passivation techniques could address the instability issue through several popular strategies, such as surface capping ligands and interfacial layers. Very recently, an alternative passivation approach to protect the unstable Sn‐based perovskites has been reported . In this work, by alloying Sn with Ge, an ultrathin (≈5 nm) native‐oxide layer is formed on top of the perovskite surface, thus protecting it and overcoming its typical instability problems.…”

Tailoring C60 for Efficient Inorganic CsPbI2Br Perovskite Solar Cells and Modules

“…The current–voltage response also shows the reduced slope for the TPFPB‐doped device (Figure S7, Supporting Information), which is consistent with the results of the c‐AFM current maps (Figure d,e). In addition, the electron mobility of C 60 and 4 wt% TPFPB‐doped C 60 films have been evaluated by means of the SCLC model with the equation of j = (9 µε 0 ε r V 2 )/8 L 3 , where µ is the electron carrier mobility, ε 0 is the vacuum permittivity, ε r is the relative permittivity of C 60 , V is the applied voltage, and L is the film thickness . The mobility of the 4 wt% TPFPB‐doped C 60 film is reduced from 1.67 to 0.39 cm 2 V −1 s −1 (Figure S8, Supporting Information).…”