Universal Dynamic Liquid Interface for Healing Perovskite Solar Cells

Abstract

These inhomogeneous defects in turn causes an accelerated charge recombination and a poor durability if they cannot be timely eliminated during the practical application. Therefore, it is a challenge to make a real-time self-healing Healing charge-selective contact interfaces in perovskite solar cells (PSCs) highly determines the power conversion efficiency (PCE) and stability. However, the state-of-the-art strategies are often static by oneoff formation of a functional interlayer, which delivers fixed interfacial properties during the subsequent operation. As a result, defects formed in-service will gradually deteriorate the photovoltaic performances. Herein, a dynamic healing interface (DHI) is presented by incorporating a low-melting-point small molecule onto perovskite film surface for highly efficient and stable PSCs. Arising from the reduced non-radiative recombination, the DHI boosts the PCE to 12.05% for an all-inorganic CsPbIBr 2 solar cell and 14.14% for a CsPbI 2 Br cell, as well as 23.37% for an FA 0.92 MA 0.08 PbI 3 (FA = formamidinium, MA = methylammonium) cell. The solid-to-liquid phase conversion of DHI at elevated temperature causes a longitudinal infiltration into the bulk perovskite film to maximize the charge extraction, passivate defects at grain boundaries, and suppress ion migration. Furthermore, the stability is remarkably enhanced under air, heat, and persistent light-irradiation conditions, paving a universal strategy for advanced perovskite-based optoelectronics.

Lewis Acid–Base Adducts for Efficient and Stable Cesium‐Based Lead Iodide‐Rich Perovskite Solar Cells

“…[40] In the first stage, such as 0-0.54 ps for the pristine and PF 6 − CsPbTh 3 films, and 0-2.2 ps for LABAs-CsPbTh 3 , free charge carriers are spontaneously formed due to the Wannier-Mott-type excitons in 3D perovskite, and then the charge carriers suffer from bimolecular recombination and trap-assisted monomolecular recombination with lifetimes of over hundreds of picoseconds and thousands of picoseconds, respectively. [41] Therefore, the decay ratio of the PB signal represents the charge transfer or recombination process. Compared with the pristine and PF 6 − CsPbTh 3 samples, the LABAs-CsPbTh 3 shows a much slower decay ratio, with ΔA decreasing to 45.58% for pristine material and 52.82% for PF 6 − -CsPbTh 3 at 40.15 ns, while a higher ratio of 68.17% for LABAs-CsPbTh 3 is achieved at the same time.…”

Cation Engineering by Three‐Dimensional Organic Spacer Cations for Effective Defect Passivation in Perovskite Solar Cells

“…The slope of 1.65 K B T/e of the DABCO 2 + modified device is lower than the slope of 1.96 K B T/e of the control device, showing the trap states in optoelectronic induced recombination process, [15] and suggesting the effective passivation treatment of DABCO 2 + for reducing trap-assisted carrier recombination. [31][32] The Nyquist plots for the control and DABCO 2 + passivated PSC were tested from 1 Hz to 1 MHz at 0.1 V bias in the darkness (Figure 3b). The recombination resistance (Rrec) from the impedance spectroscopy could reflect the charge recombination is 5.56 kΩ and 0.92 kΩ for control and DABCO 2 + modified PSCs, respectively.…”

Carbon-Based CsPbI3 Perovskite Solar Cells

“…By employing CsPbI 3-x Br x as light absorbers in C-PSCs, the light absorption range was extended and the short-circuit current density (Jsc) was improved. As a result, the champion PCE of 12.05% [11] and 15.24% [12] were achieved by CsPbIBr 2 and CsPbI 2 Br C-PSCs, respectively.…”