Air-processed stable near-infrared Si-based perovskite light-emitting devices with efficiency exceeding 7.5%

Abstract

Two composite layers are used to enhance the efficiency of Si-based near-infrared perovskite light-emitting devices, which are produced in ambient air, and the external quantum efficiency increased to 7.5%.

High‐Efficiency Air‐Processed Si‐Based Perovskite Light‐Emitting Devices via PMMA‐TBAPF6 Co‐Doping

“…The reference device and P‐device have the EQE of 5.6% and 7.5%, which is measured in a previous work. [ 9 ] With P‐T co‐doping, the c‐device displays an EQE up to 10.4% under 300 mA cm −2 , suggesting better EL efficiency can be achieved by simple anti‐solvent engineering method.…”

“…Obviously, neither precursor‐doping (twofold increasing) nor anti‐solvent single‐doping (threefold increasing) shows a significant enhancement on PL intensity, implying that PMMA plays an indispensable role in co‐doping method. In a previous work, [ 9 ] we promoted the PMMA‐doped air‐processed MAPbI 3 film with remarkable stability. The PMMA protection improved the crystallinity of the perovskite and reduced surface defects, thus the passivation effect of TBAPF 6 could be fully utilized when TBAPF 6 is co‐doped with PMMA, leading to a significant increase of PL and EL performance.…”

“…All the spin‐coating procedures are carried out in air‐ambient. The device consists of the following structures: the ITO (200 nm) acts as a cathode, the ETL is ZnO (60 nm), and the HTL is the CBP:poly‐TPD (10 nm) composite layer, [ 9 ] the p‐Si serves as the substrate and the hole‐injection layer, the active layer is the P‐T co‐doped MAPbI 3 with a thickness of ≈70 nm. Figure 2c shows the energy level diagram of the studied PeLED.…”

“…Then, we passivated the interface defects in the device [ 8 ] and adjusted the device structure to increase device efficiency. [ 9 ] Further, the surface of the perovskite was modified by PMMA anti‐solvent doping, so that the device can operate normally in a high humidity atmosphere, and an EQE of 7.5% is obtained. [ 9 ] However, although the PMMA protects perovskite from degradation in the air and passivates the perovskite surface, the passivation is not comparable to other materials.…”

“…[9] Further, the surface of the perovskite was modified by PMMA anti-solvent doping, so that the device can operate normally in a high humidity atmosphere, and an EQE of 7.5% is obtained. [9] However, although the PMMA protects perovskite from degradation in the air and passivates the perovskite surface, the passivation is not comparable to other materials. [10][11][12] Also, with PMMA doping, the roughness of MAPbI 3 surface increases (Figure S1, Supporting Information).…”