85 °C/85%‐Stable n‐i‐p Perovskite Photovoltaics with NiO_x Hole Transport Layers Promoted By Perovskite Quantum Dots

Abstract

Power conversion efficiency (PCE) and long‐term stability are two vital issues for perovskite solar cells (PSCs). However, there is still a lack of suitable hole transport layers (HTLs) to endow PSCs with both high efficiency and stability. Here, NiOx nanoparticles are promoted as an efficient and 85 °C/85%‐stable inorganic HTL for high‐performance n‐i‐p PSCs, with the introduction of perovskite quantum dots (QDs) between perovskite and NiOx as systematic interfacial engineering. The QD intercalation enhances film morphology and assembly regulation of NiOx HTLs . Due to structure–function correlations, hole mobility within NiOx HTL is improved. And the hole extraction from perovskite to NiOx is also facilitated, resulting from reduced trap states and optimized energy level alignments. Hence, the promoted NiOx‐based n‐i‐p PSCs exhibit high PCE (21.59%) and excellent stability (sustaining 85 °C aging in air without encapsulation). Furthermore, encapsulated solar modules with QDs‐promoted NiOx HTLs show impressive stability during 85 °C/85% aging test for 1000 hours. With high transparency, QDs‐promoted NiOx is also demonstrated to be an advanced HTL for semitransparent PSCs. This work develops promising NiOx inorganic HTL in n‐i‐p PSCs for manufacturing next‐generation photovoltaic devices.

Moisture‐Resilient Perovskite Solar Cells for Enhanced Stability

“…[9,13,25,30,34,41,45,46,48,50,52,[54][55][56]81,83,84,88,89,[91][92][93]96,[100][101][102][103] f) Damp heat stability results from various top surface passivation strategies. [13,45,46,48,84,88,92,99] surface against moisture, heat, and light exposure. Depending on their precise location in the device, broadband optical transparency, compatibility with subsequent device processing, and material cost are additional requirements to consider.…”

Phase-Engineering of Layered Nickel Hydroxide for Synthesizing High-Quality NiOx Nanocrystals for Efficient Inverted Flexible Perovskite Solar Cells

“…Previous studies have shown that the V OC enhancement may be attributed to a better energy level alignment within the devices. 34,46,63 We first investigated the energy level difference between the NiO x -NaOH and NiO x -KOH films using ultraviolet photoelectron spectroscopy (UPS) measurements. 12,29 We first inspected the hole transfer at the NiO x /perovskite interface.…”

“…One is organic functional materials, such as poly [bis (4-phenyl) (2,4,6-trimethylphenyl)-amine] (PTAA), poly­(3,4-ethylene dioxythiophene)–polystyrene sulfonate (PEDOT: PSS), polythiophene, and so on. ,− Although these organic functional materials have been successfully applied, they suffer from long-term stability, high cost, and batch-to-batch reproducibility. The second one is inorganic semiconductor materials, such as NiO x , CuSCN, Cu 2 O, etc. − Among them, NiO x is an essential material with excellent characteristics, including low cost, diverse preparation methods, and excellent thermal stability. ,,− More importantly, it has an ideal energetic alignment with perovskite materials. Thus it has become a famous star in the field of inverted PSCs in recent years.…”

Effective Hole Transfer from CH(NH2)2PbI3 Perovskite Quantum Dots to Conjugated Polymers: A Bridge for Carrier Extraction by the Organic Hole-Transporting Layer

“…The ineffective hole extraction due to the large surface energy difference between PQDs and an organic HTL is one of the main reasons limiting the power conversion efficiency (PCE) of perovskite-based devices. 22,23 A heterointerface consisting of a conjugated polymer and PQDs is an alternative strategy to provide an additional channel to facilitate the CT. 24 In such a structure, a graded energy level can be formed and the photogenerated holes in the PQDs are first transferred to the polymer and then extracted by the HTL, thus circumventing the obstacle of direct hole transfer from PQDs to the HTL. In addition, the mixing of PQDs and polymers improves the resistance from water and light to achieve high stability.…”

“…The efficiency of hole transfer from pure PQDs to the HTL may not be satisfactory, in particular for the HTL PTAA, , which has higher hole mobility and is cheaper than Spiro-OMeTAD and considered as the ideal choice for the practical device applications. The ineffective hole extraction due to the large surface energy difference between PQDs and an organic HTL is one of the main reasons limiting the power conversion efficiency (PCE) of perovskite-based devices. , A heterointerface consisting of a conjugated polymer and PQDs is an alternative strategy to provide an additional channel to facilitate the CT . In such a structure, a graded energy level can be formed and the photogenerated holes in the PQDs are first transferred to the polymer and then extracted by the HTL, thus circumventing the obstacle of direct hole transfer from PQDs to the HTL.…”