Efficient and Stable Perovskite Solar Cells with a High Open‐Circuit Voltage Over 1.2 V Achieved by a Dual‐Side Passivation Layer

Abstract

Suppressing nonradiative recombination at the interface between the organometal halide perovskite (PVK) and the charge‐transport layer (CTL) is crucial for improving the efficiency and stability of PVK‐based solar cells (PSCs). Here, a new bathocuproine (BCP)‐based nonconjugated polyelectrolyte (poly‐BCP) is synthesized and this is introduced as a “dual‐side passivation layer” between the tin oxide (SnO2) CTL and the PVK absorber. Poly‐BCP significantly suppresses both bulk and interfacial nonradiative recombination by passivating oxygen‐vacancy defects from the SnO2 side and simultaneously scavenges ionic defects from the other (PVK) side. Therefore, PSCs with poly‐BCP exhibits a high power conversion efficiency (PCE) of 24.4% and a high open‐circuit voltage of 1.21 V with a reduced voltage loss (PVK bandgap of 1.56 eV). The non‐encapsulated PSCs also show excellent long‐term stability by retaining 93% of the initial PCE after 700 h under continuous 1‐sun irradiation in nitrogen atmosphere conditions.

24.96%‐Efficiency FACsPbI3 Perovskite Solar Cells Enabled by an Asymmetric 1,3‐Thiazole‐2,4‐Diammonium

“…To quantitatively study the effect of TDA modification on the defect state density of devices, the trap-state density (N trap ) of the devices is estimated with electron-only devices by the space-charge limited current method (SCLC) (Figure 5i). [55] The N trap is calculated from the trap-filled limit voltage (V TFL ) in Figure 5i, corresponding to 8.09 × 10 15 and 4.45 × 10 15 cm −3 for control and target devices, respectively. Obviously, the defect state density is successfully reduced after TDA modification.…”

25.24%‐Efficiency FACsPbI3 Perovskite Solar Cells Enabled by Intermolecular Esterification Reaction of DL‐Carnitine Hydrochloride

“…For SnO 2 ETL, the defects mainly come from the oxygen vacancies (V O ) and interstitial tin atoms (Sn i ), [10,11] which can lead to charge carriers accumulation and nonradiative recombination loss at interface. A large number of bulk additives or surface modifiers, such as metal cations, [12][13][14][15] inorganic salts, [16][17][18][19] organic salts, [20][21][22][23][24][25] organic small molecules, [26][27][28][29][30][31] and polymers [32][33][34][35] have been developed to reduce V O and Sn i defects in SnO 2 ETL. Among them, the organic ammonium chloride matrix, in which chloride can dope V O and the N atom can bind with Sn i via Lewis acid-base interaction, has been developed as one of the most effective compounds to reduce the defects in SnO 2 ETL.…”

Dual Interface Passivation in Mixed-Halide Perovskite Solar Cells by Bilateral Amine

“…The intensity of the diffraction peak (001) and the (002) plane increased significantly for the target films, which indicates better perovskite grain growth. 47 There was no 2D perovskite peak observed from the target thin films, which indicates that DPAC is located at the outer layer of the perovskite thin film. We infer that DPAC is adsorbed at the perovskite surface.…”