p‐Type Charge Transfer Doping of Graphene Oxide with (NiCo)_1−yFe_yO_x for Air‐Stable, All‐Inorganic CsPbIBr₂ Perovskite Solar Cells

Abstract

The precise regulation of interfacial charge distribution highly determines the power conversion efficiency of perovskite solar cells (PSCs). Herein, inorganic (NiCo)1−yFeyOx nanoparticle decorated graphene oxide (GO) is successfully demonstrated as a hole booster for all‐inorganic CsPbIBr2 PSC free of precious metal electrode. Arising from the spontaneous electron transfer induced p‐type doping of GO from edged oxygen‐containing functional groups to (NiCo)1−yFeyOx, the best all‐inorganic CsPbIBr2 PSC achieves an efficiency of 10.95 % under one standard sun owing to the eliminated paradox between charge extraction and charge localization in GO surface. Furthermore, the champion device exhibits an excellent long‐term stability at 10 % relative humidity without encapsulation over 70 days because of the suppressed ions migration.

Stretchable alkenamides terminated Ti3C2Tx MXenes to release strain for lattice‐stable mixed‐halide perovskite solar cells with suppressed halide segregation

“…As shown in Figure 1A,B, TEM images of MXenes with and without alkenamides termination both show 2D nanosheets with a size of 20 nm, demonstrating the negligible effect on morphology after alkenamides functionalization. However, the crystallinity is slightly weakened (the insets in Figures 1A,B and ), which benefits in increasing the dispersibility owing to the reduced interlayer van der Waals force (Figure ) 29 . To preliminarily confirm the successful commensality, we further performed the EDS mapping images of the SAM sample, as shown in Figures and 1C–F; Ti, C, O, and N elements are clearly detected, comprehensibly assigning to the Ti 3 C 2 MXene and alkenamides group.…”

Synergistic Effect of Surface p‐Doping and Passivation Improves the Efficiency, Stability, and Reduces Lead Leakage in All‐Inorganic CsPbIBr2‐Based Perovskite Solar Cells

“…Perovskite solar cells (PSCs) have sparked great inspiration from researchers due to their facile preparation method, low cost, and excellent optoelectronic performance, such as the based on CsPbIBr 2 can not only achieve a high PCE in singlejunction structure and excellent stability but also can improve the low limit of J sc in tandem cells. [31,32] However, wide-bandgap perovskite solar cells suffer from severe open-circuit voltage loss and phase separation, which affect their photoelectric conversion efficiency and stability. [33] There are many defects in polycrystalline films prepared by the solution method.…”

Van der Waals Epitaxial Growth for High Performance Organic‐Free Perovskite Solar Cell: Experimental and Theoretical Insights

“…The GO decorated nanoparticles included PSC yielded a very nice V OC of 1.29 V and an improved PCE of 10.95%. [ 17 ] Crystallization kinetics of PAL such as surface morphology and structural crystallography have crucial significance to derive the high performance of PSC devices, which are strongly dependent on the substrates’ smoothness and uniformity. Among few reported techniques for substrate modifications, van der Waals (VdW) epitaxy is a predominant strategy for synthesizing semiconductor thin films of high quality.…”

“…[14,16] Wide bandgap perovskites have the potential to enhance the stability of bottom cells against ultraviolet radiation and act as filters in tandem cell configurations. [14] CsPbIBr 2 with a wide bandgap of 2.03 eV is a nice choice with enhanced phase stability, suitable absorption threshold and its immunity to withstand heat, illumination, and humidity mishmashes, [17,18] which is also the research focus of this work. As the matter of fact, the highest reported PCE of CsPbIBr 2 is still far away from its theoretical values (17.25%), [7,8] which is attributed to substantial nonradiative and interface recombination of photo-enhanced charge carriers.…”

“…The segregated minority phases are well known as carrier trapping sites in PAL bulk, [19] which are responsible for losses like E loss (E loss = E g − eV OC ) restricting the V OC of the overall PSC device. [20] Several strategies to reduce the E loss , and boost PCE of CsPbIBr 2 based PSCs are reported to date, such as additive engineering, [19,21] compositional engineering, [22,23] and heteroatom doping to substitutionally replace the cesium (Cs)-, and Pb-sites, [17,18] and interface engineering, [24][25][26] etc.…”