Inverted All-Inorganic CsPbI₂Br Perovskite Solar Cells with Promoted Efficiency and Stability by Nickel Incorporation

Abstract

All-inorganic CsPbI2Br perovskite solar cell with an inverted architecture of indium-tin oxide/poly­[3-(4-carboxylbutyl)­thiophene]/CsPbI2Br/(6,6)-phenyl-C61-butyric acid methyl ester/C60/bathocuproine/Ag was fabricated. Together with the incorporation of nickel iodide, perovskite crystallinity and film morphology were promoted. Also, suppressed trap-state density in perovskite film was accomplished due to the passivation effect. Consequently, enhanced champion efficiency of 13.88% with V OC of 1.141 V, J SC of 16.02 mA/cm2, and fill factor of 75.96% was delivered by the doped optimal device, compared with the efficiency of 11.97% of the reference device. Superior device stability was demonstrated for the optimal device both in ambient atmosphere and N2-filled glovebox, without encapsulation. Moreover, improved light stability was also confirmed for optimal device by prolonged operation time, under continuous illumination of simulated solar spectrum. In addition, high-temperature annealing or sintering of interlayer was eliminated by utilizing solution-processed poly­[3-(4-carboxylbutyl)­thiophene]-CH3NH2 (P3CT-CH3NH2) as the hole-transport layer. This work provides an alternative inverted architecture and an effective ion-doping strategy for efficient and stable all-inorganic perovskite solar cells (PSCs), which would help promote the development of PSC technology.

Dopant‐Free Organic Hole‐Transporting Material for Efficient and Stable Inverted All‐Inorganic and Hybrid Perovskite Solar Cells

“…[ 21 ] In contrast, all‐inorganic PVSCs with an inverted (p–i–n) [ 22 ] architecture can avoid these drawbacks with diversified device configuration. [ 23 ] Moreover, the inverted all‐inorganic PVSCs are favorable for the construction of tandem solar cells as most of all‐perovskite tandem solar cells are fabricated with inverted layouts. [ 24–27 ] Nevertheless, most research of all‐inorganic PVSCs focus on the convention structure.…”

“…To date, the highest stabilized efficiency of the all‐inorganic PVSCs based on the inverted structure is only about 14%. [ 23 ] One of the reasons limiting the progress of the inverted structure is the lack of appropriate interfacial materials, particularly the HTMs, which strongly affect charge recombination, hole transport and extraction. [ 28–31 ] Widely used inorganic HTMs in PVSCs include CuSCN, NiO x , etc., [ 32–36 ] which are typically considered more stable than organic HTMs, but their relatively low intrinsic conductivity and surface defects limit the PCE of the device.…”

“…The as‐optimized all‐inorganic device realized a champion PCE value of 15.4% with a remarkable stabilized power output (SPO) of ≈14.3% within 650 s. To the best of our knowledge, this is one of the highest efficiencies achieved in inverted all‐inorganic PVSCs. [ 23 ] To demonstrate the generality this HTM, we also fabricated the hybrid inverted PVSC with a TPE‐S layer, which shows an outstanding PCE of 21.0%, approaching the record (21.6%) for inverted PVSCs. [ 49,50 ] The morphological characterizations and device physics studies suggest that the improved performance can be attributed to several aspects including: i) the improvement of the crystallinity of the perovskite film deposited on the TPE‐S layer, which suppresses undesired charge carrier recombinations; ii) TPE‐S exhibits high transparency in visible region and chemical PH neutrality, which is beneficial for long‐term stability.…”

Improving the Stability and Optoelectronic Properties of All Inorganic Less‐Pb Perovskites by B‐Site Doping for High‐Performance Inorganic Perovskite Solar Cells

“…[80] Copyright 2019, Wiley-VCH. [83] However, Ni 2þ -doped CsPbI 2 Br perovskite showed a slight blue shift in absorption spectra compared with the undoped one. The radius of Cu 2þ (0.73 Å) is the same as those of Zn 2þ and Ni 2þ .…”

Enhancing Built‐In Electric Field and Defect Passivation through Gradient Doping in Inverted CsPbI2Br Perovskite Solar Cells

“…To date, champion PCEs of 17.03% and 15.92% have been achieved for n–i–p‐type (normal) and p–i–n (inverted)‐type PeSCs, respectively, both based on CsPbI 2 Br. [ 12–18 ] Nevertheless, such PCE values are still lower than those of hybrid PeSCs. Further improvement is highly demanded for all‐inorganic PeSCs.…”