Minimizing non-radiative recombination losses in perovskite solar cells

Abstract

Photovoltaic solar cells based on metal halide perovskites have gained considerable attention over the past decade because of their potentially low production cost, earth-abundant raw materials, ease of fabrication and ever-increasing power conversion efficiencies of up to 25.2%. This type of solar cells offers the promise of generating electricity at a more competitive unit price than traditional fossil fuels by 2035.Nevertheless, the best research cell efficiencies are still below the theoretical limit defined by the Shockley-Queissier theory owing to the presence of non-radiative recombination losses. In this Review, we analyse the predominant pathways that contribute to nonradiative recombination losses in perovskite solar cells, and evaluate their impact on device performance. We then discuss how non-radiative recombination losses can be estimated through reliable characterization techniques, and highlight some notable advances in mitigating these losses, which hint at pathways towards defect-free perovskite solar cells.

Suppressing Defects‐Induced Nonradiative Recombination for Efficient Perovskite Solar Cells through Green Antisolvent Engineering

“…[13] From previous studies, it is known that defectsinduced nonradiative recombination is the predominant recombination that degrades the solution pro cessed PSCs performance. [10,[15][16][17] Timeresolved fluorescence (TRF) measurements show that the estimated defects states of 1.6 × 10 17 cm −3 for surface is higher than 5.0 × 10 16 cm −3 for bulk perovskite, [18] and transient reflection spectroscopy meas urements show that management of surface recombination is more important than that of recombination inside grains. [19] Therefore, suppressing surface defectsinduced nonradiative recombination plays a critical role in improving PSCs perfor mance.…”

“…The decreased ΔV OC,nonrad implies that a suppressed defectsinduced non radiative recombination which contributes to an enhanced V OC for MABrEthPSCs. [17] To further evaluate the charge carrier lifetime in fully oper ating devices, the transient photovoltage (TPV) of PSCs was conducted. [56][57][58] Upon the illumination of pulse light, the pho tocarriers were generated to create free electrons and holes as well as the generation of photovoltage.…”

Self‐Crystallized Multifunctional 2D Perovskite for Efficient and Stable Perovskite Solar Cells

“…[ 7 ] Nevertheless, 3D perovskite light absorbers have suffered from high defect density at the surfaces and grain boundaries, which can lead to nonradiative recombination and decrease PCEs of PSC. [ 6,8 ] Also, the volatile organic cation in the 3D perovskite lattice such as methylammonium (MA + ) and formamidinium (FA + ) degrades the stability of the perovskite itself and lifetime of PSCs. [ 9,10 ] In this regard, 2D perovskites have recently received substantial attention as they contain less‐volatile bulkier organic cations, which can trigger passivation effect and lead to better water resistance, resulting in higher PCE and extended long‐term stability of PSCs.…”

Low‐Dimensional Contact Layers for Enhanced Perovskite Photodiodes

“…[ 6,17,18 ] Typically, nonwetting surfaces can considerably reduce the density of defects present at the grain boundaries by increasing the perovskite grain size. [ 19–21 ] By minimizing compressive or tensile strains at the bottom interface, high‐quality films with lower defects have already been realized. [ 22,23 ] Furthermore, fine‐tuned bromide ratios near the bottom interface have proven to be an effective strategy to regulate defects and the built‐in potential of perovskite devices.…”