Stabilizing heterostructures of soft perovskite semiconductors

Abstract

Here we report a solution-processing strategy to stabilize the perovskite-based heterostructure. Strong Pb–Cl and Pb–O bonds formed between a [CH(NH2)2]x[CH3NH3]1−xPb1+yI3 film with a Pb-rich surface and a chlorinated graphene oxide layer. The constructed heterostructure can selectively extract photogenerated charge carriers and impede the loss of decomposed components from soft perovskites, thereby reducing damage to the organic charge-transporting semiconductors. Perovskite solar cells with an aperture area of 1.02 square centimeters maintained 90% of their initial efficiency of 21% after operation at the maximum power point under AM1.5G solar light (100 milliwatts per square centimeter) at 60°C for 1000 hours. The stabilized output efficiency of the aged device was further certified by an accredited test center.

Multi-component engineering to enable long-term operational stability of perovskite solar cells

“…Some of them aim to prevent the permeation of humidity and oxygen and to block the out-diffusion of ions and volatile species from the perovskite layer. This has been achieved by interface engineering or by the application of stable transporting layers, electrodes and interlayers [41][42][43][44][45]. Further strategies focus on the perovskite layer itself, which can be compositional and additive engineered, to enhance its robustness under stress factors [32,36,46,47].…”

“…Enormous efforts have been made to improve the stability as well as the efficiency of hybrid PSCs. Recently, hybrid PSCs with an efficiency higher than 20% have demonstrated excellent stability of over 1000 h under one sun at temperatures above 60 • C. This is achieved by using ionic liquid additives [46], or via interface engineering with wide band gap PbSO 4 salts [43] or chlorinated graphene oxide [42], or through the replacement of unstable N2,N2,N2 ′ ,N2 ′ ,N7,N7,N7,N7 ′ -octakis(4-methoxyphenyl)-9,9 ′ -spirobi[9 H-fluorene]-2,2 ′ ,7,7 ′ -tetramine (Spiro-OMeTAD) hole transporting layer (HTL) by the inorganic CuSCN [44]. The estimated T 80 (time at a performance loss of 20%) of high efficiency hybrid PSCs at 70 • C-75 • C is less than 6000 h [46], indicating a huge improvement, although there is still considerable research required before realizing practical applications.…”

“…It can also be observed that when the stress temperature is below 70 • C, the application of a single strategy, such as the modification of one component of the device, can lead to stable PSCs. Some of these strategies include the use of inorganic transporting layers or interlayers [42,68], the engineering of perovskite composition [63,69], or the encapsulation with highly hydrophobic photocurable fluoropolymers [70]. Above 70 • C, different strategies are combined to achieve exceptional long-term stability [35,36,46].…”

Enhanced emission from CH3NH3PbBr3 perovskite films by graphene quantum dot modification

“…Organic-inorganic hybrid perovskites have attracted significant interest in solution processed high-performance optoelectronic devices [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Besides the great success in photovoltaics, their unique optical and electrical properties make hybrid perovskites promising candidates for next generation light emitting diodes (LEDs) [19][20][21][22][23][24][25][26].…”

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

“…[1][2][3][4] However, the notorious long-term instability is still a great burden for their commercialization under realistic operation conditions. [5,6] Strategies including composition engineering, encapsulation technology, and surface stabilization have been performed to enhance the device stability, [7][8][9] however the thermodynamically spontaneous ion migration of volatile organic components still causes an inevitable performance degradation under the stimuli of light irradiation and/or electric field. [10] Therefore, the full substitution of organic species by inorganic cesium ions to form all-inorganic cesium lead halide perovskites is considered as a promising solution to stabilize the device performance.…”