Rational Surface‐Defect Control via Designed Passivation for High‐Efficiency Inorganic Perovskite Solar Cells

Abstract

Iodine vacancies (V I ) and undercoordinated Pb 2+ on the surface of all-inorganic perovskite films are mainly responsible for nonradiative charge recombination. An environmentally benign material, histamine (HA), is used to passivate the V I in perovskite films. A theoretical study shows that HA bonds to the V I on the surface of the perovskite film via a Lewis base-acid interaction; an additional hydrogen bond (H-bond) strengthens such interaction owing to the favorable molecular configuration of HA. Undercoordinated Pb 2+ and Pb clusters are passivated, leading to significantly reduced surface trap density and prolonged charge lifetime within the perovskite films. HA passivation also induces an upward shift of the energy band edge of the perovskite layer, facilitating interfacial hole transfer. The combination of the above raises the solar cell efficiency from 19.5 to 20.8 % under 100 mW cm À2 illumination, the highest efficiency so far for inorganic metal halide perovskite solar cells (PSCs).

Synergetic interfacial passivation, band alignment, and long-term stability with halide-optimized CsPbBrxI3−x nanocrystals for high-efficiency MAPbI3 solar cells

“…S13 (ESI †) shows the I-V characteristics of the electron-only device with the structure of ITO/SnO 2 /MAPbI 3 / CsPbBr 1.2 I 1.8 NCs/PCBM/Ag. According to a previous study, 38 the defect densities (N trap ) were calculated using the following equation:…”

Highly Efficient and Stable CsPbTh3 (Th = I, Br, Cl) Perovskite Solar Cells by Combinational Passivation Strategy

“…[1][2][3][4][5][6][7] In recent years, the power conversion efficiency (PCE) of CsPbI 3 perovskite solar cells (PSCs) climbed rapidly from 2.9% first reported by Snaith and coworkers to 20.8% by Liu and co-workers, and the efficiency gap between the CsPbI 3 and organic-inorganic hybrid PSCs is further reduced. [8][9][10][11][12] Furthermore, CsPbI 3 has a suitable bandgap (≈1.70 eV) and can be used as the top cell of tandem photovoltaic cells. [13,14] Up to date, the introduction of small DMA = (CH 3 ) 2 NH 2 + organic cations into precursor solution is essential to approach efficient and stable CsPbI 3 PSCs.…”

“…[ 1 , 2 , 3 , 4 , 5 , 6 , 7 ] In recent years, the power conversion efficiency (PCE) of CsPbI 3 perovskite solar cells (PSCs) climbed rapidly from 2.9% first reported by Snaith and co‐workers to 20.8% by Liu and co‐workers, and the efficiency gap between the CsPbI 3 and organic–inorganic hybrid PSCs is further reduced. [ 8 , 9 , 10 , 11 , 12 ] Furthermore, CsPbI 3 has a suitable bandgap (≈1.70 eV) and can be used as the top cell of tandem photovoltaic cells. [ 13 , 14 ]…”

Defect healingviaa gradient cooling strategy for efficient all-inorganic perovskite solar cells

“…Very recently, a PCE of up to 20.8% was reported for CsPbI 3Àx Br x by surface passivation with 2-(1H-imidazol-4-yl)ethanamine. 12 In spite of the above impressive progress made in the CsPbX 3 perovskites, the control of loss in open-circuit voltage (V oc ) and fill factor (FF) still lags behind that in the case of organic-inorganic perovskites, 13 mainly due to the defect induced non-radiative recombination. 14,15 Therefore, the healing of defects is critical to maximize the performance of CsPbX 3 perovskites.…”