High-Performance Perovskite Solar Cells by One-Step Self-Assembled Perovskite-Polymer Thin Films

Abstract

Perovskite materials have drawn the greatest attention as alternatives for approaching cost-effective perovskite solar cells (PSCs) in the past decade. However, the desire for PSCs with photocurrent hysteresis-free characteristics has been unfulfilled due to the intrinsic foibles of perovskite materials. In this study, PSCs with boosted power conversion efficiency (PCEs), dramatically suppressed photocurrent hysteresis, and significantly boosted stability through one-step self-assembled methylammonium lead iodide (CH 3 NH 3 PbI 3 ) cocrystallized with poly(ethylene oxide) (PEO) are reported. It is found that one-step selfassembled CH 3 NH 3 PbI 3 cocrystallized with PEO could generate high-quality thin film with significantly enlarged crystal grains through weak hydrogen interactions between CH 3 NH 3 PbI 3 and PEO. Further studies demonstrate that one-step self-assembled PEO−CH 3 NH 3 PbI 3 thin films possess improved charge carrier transport, reduced charge carrier recombination, and promoted charge carrier extraction time as compared with those of one-step self-assembled processed CH 3 NH 3 PbI 3 thin film. As a result, PSCs by one-step self-assembled PEO− CH 3 NH 3 PbI 3 thin films exhibit a PCE of 20.78%, which is an over 20% enhancement compared to that (17.42%) from PSCs by onestep self-assembled CH 3 NH 3 PbI 3 thin films. Moreover, PSCs by one-step self-assembled PEO−CH 3 NH 3 PbI 3 thin films exhibit dramatically suppressed photocurrent hysteresis and significantly boosted stability. All these results demonstrate that the method of one-step self-assembled perovskites cocrystallized with polymers is a facile approach toward high-performance PSCs.

Polymer‐Assisted Phase Stable γ‐CsPbI3 Perovskite Film for Self‐Powered and Ultrafast Photodiodes

“…To our knowledge, the detectivity of device with 5% PEOXA addition is comparable to the best reported value of α‐CsPbI 3 based self‐powered photodiode. [ 31,23 ] Analogously, device with 5% of PEOXA addition exhibits the highest EQE value of 40% under 0 V bias. Comparison in efficiencies of the device under different bias voltages is shown in Figure 2e, manifesting a positive correlation of the EQE values with the bias voltage.…”

“…[27] Zheng et al further investigated high-performance perovskite photovoltaics by one-step self-assembled polymerperovskite thin film, achieving dramatically suppressed hysteresis and boosted stability. [23] Unfortunately, the quantity of researches on stable CsPbI 3 -based thin film photodetectors are relatively limited and somewhat unsatisfactory. [1,28] It has been reported that CsPbI 3 exists in different black phases, including cubic(α)-CsPbI 3 , orthorhombic(γ)-CsPbI 3 , and tetragonal(β)-CsPbI 3 .…”

“…Alternatively, introducing polymer additives have become promising ways to stabilize the perovskite structure and improving the performance of perovskite‐based photovoltaics. [ 23 ] They are effective in freezing counterions’ migration and manipulating perovskite crystalline formation via strong bonding interactions between functional groups and crystalline cations. [ 24–27 ] Bansode et al.…”

“…further investigated high‐performance perovskite photovoltaics by one‐step self‐assembled polymer‐perovskite thin film, achieving dramatically suppressed hysteresis and boosted stability. [ 23 ] Unfortunately, the quantity of researches on stable CsPbI 3 ‐based thin film photodetectors are relatively limited and somewhat unsatisfactory. [ 1,28 ]…”

“…Alternatively, introducing polymer additives have become promising ways to stabilize the perovskite structure and improving the performance of perovskite-based photovoltaics. [23] They are effective in freezing counterions' migration and manipulating perovskite crystalline formation via strong bonding interactions between functional groups and crystalline cations. [24][25][26][27] Bansode et al demonstrated Lead-halide perovskite materials have emerged as promising alternatives for optoelectronic applications due to their low-cost, easily tunable bandgaps, and facile solution-processability.…”