RESUMEN
Efficient charge injection and radiative recombination are essential to achieving high-performance perovskite light-emitting diodes (Pero-LEDs). However, the perovskite emission layer (EML) and the electron transport layer (ETL) form a poor physically interfacial contact and non-negligible charge injection barrier, limiting the device performance. Herein, we utilize a phosphine oxide, 2,4,6-tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine (PO-T2T), to treat the perovskite/ETL interface and form a chemically bonded contact. Specifically, PO-T2T firmly bonds on the perovskite's surface and grain boundaries through a dative bond, effectively passivating the uncoordinated lead defects. Additionally, PO-T2T has high electron mobility and establishes an electron transport highway to bridge the ETL and EML. As a result, a maximum external quantum efficiency (EQEmax) of 22.06% (average EQEmax of 20.02 ± 1.00%) and maximum luminance (Lmax) of 103286 cd m-2 have been achieved for the champion device. Our results indicate that EML/ETL interface modifications are crucial for the fabrication of highly efficient Pero-LEDs.
RESUMEN
Until now, poly(3,4-ethylenedioxythiophene):poly(styrensulfonate) (PEDOT:PSS) is widely used in Sn-Pb perovskite solar cells (PSCs) due to its many advantages, including high optical transparency, suitable conductivity, superior wettability, and so on. However, the acidic and hydroscopic properties of the PSS component, as well as the incongruous energy level of the hole transport layer (HTL), may lead to unsatisfying interface properties and decreased device performance. Herein, by adding polyethylene glycol dimethacrylate (PEGDMA) into PEDOT:PSS, a newly crosslinked-double-network obtain of PEDOT:PSS@PEGDMA film, which could not only optimize nucleation and crystallinity of Sn-Pb perovskite films, but also suppress defect density and optimize energy level alignment at the HTL/perovskite interface. As a result, the achieves highly efficient and stable mixed Sn-Pb PSCs with an encouraging power conversion efficiency of 20.9%. Additionally, the device can maintain good stability under N2 atmosphere.
RESUMEN
Layered 2D perovskites have been extensively investigated by scientists with photovoltaics (PV) expertise due to their good environmental stability. However, a random phase distribution in the perovskite film could affect both the performance and stability of the devices. To overcome this problem, we propose multifunctional interface engineering of 2D GA2MA4Pb5I16 perovskite by employing guanidinium bromide (GABr) on top of it to optimize the secondary crystallization process. It is found that GABr treatment can facilitate to form a shiny and smooth surface of the 2D GA2MA4Pb5I16 film with excellent optoelectronic properties. Thus, we realize efficient and stable 2D perovskite solar cells (PSCs) with a champion power conversion efficiency (PCE) of 19.3% under AM 1.5G illumination. Additionally, the optimized device without encapsulation could retain 94% of the initial PCE for more than 3000 h after being stored under ambient conditions.
RESUMEN
Perovskite solar cells (PSCs) have raised research interest in scientific community because their power conversion efficiency is comparable to that of traditional commercial solar cells (i.e., amorphous Si, GaAs, and CdTe). Apart from that, PSCs are lightweight, are flexible, and have low production costs. Recently, graphene has been used as a novel material for PSC applications due to its excellent optical, electrical, and mechanical properties. The hydrophobic nature of graphene surface can provide protection against air moisture from the surrounding medium, which can improve the lifetime of devices. Herein, we review recent developments in the use of graphene for PSC applications as a conductive electrode, carrier transporting material, and stabilizer material. By exploring the application of graphene in PSCs, a new class of strategies can be developed to improve the device performance and stability before it can be commercialized in the photovoltaic market in the near future.