Interfacial Passivation of the p‐Doped Hole‐Transporting Layer Using General Insulating Polymers for High‐Performance Inverted Perovskite Solar Cells

Abstract

Organic-inorganic lead halide perovskite solar cells (PVSCs), as a competing technology with traditional inorganic solar cells, have now realized a high power conversion efficiency (PCE) of 22.1%. In PVSCs, interfacial carrier recombination is one of the dominant energy-loss mechanisms, which also results in the simultaneous loss of potential efficiency. In this work, for planar inverted PVSCs, the carrier recombination is dominated by the dopant concentration in the p-doped hole transport layers (HTLs), since the F4-TCNQ dopant induces more charge traps and electronic transmission channels, thus leading to a decrease in open-circuit voltages (V ). This issue is efficiently overcome by inserting a thin insulating polymer layer (poly(methyl methacrylate) or polystyrene) as a passivation layer with an appropriate thickness, which allows for increases in the V without significantly sacrificing the fill factor. It is believed that the passivation layer attributes to the passivation of interfacial recombination and the suppression of current leakage at the perovskite/HTL interface. By manipulating this interfacial passivation technique, a high PCE of 20.3% is achieved without hysteresis. Consequently, this versatile interfacial passivation methodology is highly useful for further improving the performance of planar inverted PVSCs.

Engineering of the Back Contact between PCBM and Metal Electrode for Planar Perovskite Solar Cells with Enhanced Efficiency and Stability

“…Figure a shows the typical current density ( J )–voltage ( V ) plots under AM 1.5G illumination (100 mW cm −2 ), and the key parameters including open‐circuit voltage ( V oc ), short‐circuit current density ( J sc ), fill factor (FF), PCE, and hysteresis index (HI) are listed in Table 1 . The control device with the bare PCBM features a PCE of 17.68% with a V oc of 1.078 V, a J sc of 21.02 mA cm −2 , and an FF of 78.05%, which is comparable to the results in literature . Upon incorporation of Isatin‐Cl and Isatin interlayers, respectively, the photovoltaic performances dramatically increase.…”

Alkyl‐Chain‐Regulated Charge Transfer in Fluorescent Inorganic CsPbBr3 Perovskite Solar Cells

“…This corresponds to the quantum tunneling layer between perovskite and QDs, which can significantly increase device performance by suppressing carrier recombination . Once the quantum tunneling layer gets too thick (>16.9 Å for 12 ‐CH 2 groups), the hindered electron transfer at the interface causes a low fill factor and an inferior efficiency, which is in accord with reported thickness of about 2 nm in literature . The large charge coulomb repulsive force between surface dipole induced positive charge centers and photogenerated holes induces sluggish charge extraction in the case of ligands with short alkyl chain.…”

High Performance Inverted Planar MAPbI3 Perovskite Solar Cells with a Simple Annealing Process

“…To explain the effect of annealing temperature on the PSCs performance, the dark J‐V curves of the devices annealed at different temperature are measured in the air ambient. Figure a shows that the dark‐current densities of the perovskite layer annealed at 90 °C was two order of magnitude lower than that annealed at 60 °C, which indicates there is a less charge carrier loss in the PSCs annealed at 90 °C, the photogenerated charges would transport more efficiently through the PSCs, suppress the charge carrier recombination and leakage current . In addition, the electrochemical impedance spectroscopy (EIS) was measured to evaluate the internal electronic properties.…”