Influence of Bulky Organo‐Ammonium Halide Additive Choice on the Flexibility and Efficiency of Perovskite Light‐Emitting Devices

Zhao, Lianfeng; Rolston, Nicholas; Lee, Kyung Min; Zhao, Xunhua; Reyes-Martinez, Marcos; Tran, Nhu L.; Yeh, Yao‐Wen; Yao, Nan; Scholes, Gregory D.; Loo, Yueh Lin; Selloni, Annabella; Dauskardt, Reinhold H.; Rand, Barry P.

doi:10.1002/adfm.201802060

Cited by 91 publications

(100 citation statements)

References 50 publications

(61 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In view of the two types of defects at the surface, we precisely design and synthesize a dual passivation additive FPMATFA. On one hand, FPMA cations have stronger hydrogen bonding with halide ions than FA cations due to the electron withdrawing of F atom so that it can suppress the formation of halide dangling bonds . On the other hand, the lone pair of electrons in TFA anions can bond with under‐coordinated lead, resulting in passivation of lead defects.…”

Section: Resultsmentioning

confidence: 99%

Dual Passivation of Perovskite Defects for Light‐Emitting Diodes with External Quantum Efficiency Exceeding 20%

Fang

Chen

Shi

et al. 2020

Adv Funct Materials

252

210

View full text Add to dashboard Cite

Solution‐processed metal halide perovskites (MHPs) have attracted much attention for applications in light‐emitting diodes (LEDs) due to their wide color gamut, high color purity, tunable emission wavelength, balanced electron/hole transportation, etc. Although MHPs are very tolerant to defects, the defects in solution‐processed perovskite LEDs (PeLEDs) still cause severe nonradiative recombination and device instability. Here, molecular design of additives for dual passivation of both lead and halide defects in perovskites is reported. A bi‐functional additive, 4‐fluorophenylmethylammonium‐trifluoroacetate (FPMATFA), is synthesized by using a simple solution process. The TFA anions and FPMA cations can bond with undercoordinated lead and halide ions, respectively, resulting in dual passivation of both lead and halide defects. In addition, the bulky FPMA group can constrain the grain growth of 3D perovskite, enhancing electron–hole capture rates and radiative recombination rates. As a result, high‐performance PeLEDs with a peak external quantum efficiency reaching 20.9% and emission wavelength at 694 nm are achieved using formamidinium‐cesium lead iodide‐bromide (FA0.33Cs0.67Pb(I0.7Br0.3)3). Furthermore, the operational lifetime of PeLEDs is also greatly improved due to the low trap density in the perovskite film.

show abstract

Section: Resultsmentioning

confidence: 99%

Dual Passivation of Perovskite Defects for Light‐Emitting Diodes with External Quantum Efficiency Exceeding 20%

Fang

Chen

Shi

et al. 2020

Adv Funct Materials

252

210

View full text Add to dashboard Cite

show abstract

“…Organic‐inorganic halide perovskites with remarkable characteristics such as excellent charge carrier mobility, high light absorption coefficient, tuneable bandgap, long charge carrier diffusion length, have drawn exceptional attention . The power conversion efficiencies (PCEs) of single‐junction perovskite solar cells (PSCs) have improved originally from 3.8% to currently over 23%, making it one of the most competitive materials in the photovoltaic community …”

Section: Introductionmentioning

confidence: 99%

The Positive Function of Incorporation of Small Molecules into Perovskite Materials for High‐Efficient Stable Solar Cells

et al. 2019

View full text Add to dashboard Cite

The additive engineering to hybrid organic‐inorganic perovskite precursors is an effective technique toward highly efficient stable photovoltaic devices, however, there is still a deficiency in fundamental understanding on how these additives affect the perovskite film and device performance as well. Herein is introduced a small organic molecule, DRCN5T, into a double‐cation perovskite precursor and the function on device performance is systematically investigated. An appropriate amount of DRCN5T into the precursor can promote the crystallization of film with successful suppression of δ‐FAPbI3 phase, reduce grain boundaries and adequately passivate the native defect sites. In addition, the incorporation of DRCN5T also regulates the energy level alignment of the perovskite to charge transport layer suitably. This leads to the promotion of charge transport, reduction in non‐radiative recombination, and boosts the efficiency to a value of 20.60% with greatly reduced hysteresis in the device. Moreover, the treatment by DRCN5T also significantly increases the stability of the devices in ambient environment. These findings open the gate to produce highly crystallized perovskite/organic‐molecule active layers toward commercialization of perovskite solar cells.

show abstract

“…Furthermore, in order to demonstrate the versatility of this method, another large‐cation ligand, that is, 4‐fluorobenzylammonium bromide (F‐BZABr) was incorporated to replace BABr. Previously, F‐BZABr was reported to provide better device performance than BABr . In this case, the mixed 2D/3D perovskite films were made with an F‐BZABr:PbBr 2 ratio of 1:4, which is the optimum for the case of BABr.…”

Section: Resultsmentioning

confidence: 99%

Exploiting Two‐Step Processed Mixed 2D/3D Perovskites for Bright Green Light Emitting Diodes

Yan

Croes

Fakharuddin

et al. 2019

Advanced Optical Materials

View full text Add to dashboard Cite

Mixed 2D/3D perovskite films with self‐assembled quantum wells have significantly improved the performance of perovskite light emitting diodes (PeLEDs). In this work, such films are fabricated through a two‐step interdiffusion method that is widely employed in processing of perovskite solar cells, however, remains rarely explored for PeLEDs. The effects of incorporating large‐cation ligand, i.e., butylammonium bromide (BABr) into formamidinium lead bromide (FAPbBr3) based perovskites, in terms of film composition, morphology, optoelectronic properties as well as device performance are thoroughly investigated in this method. By modulating BABr:PbBr2 ratio in the precursor solution, the optimal device shows a maximum external quantum efficiency (EQE) of 7.36% at 147.7 mA cm−2 and a brightness of 37 720 Cd m−2 at 5 V. The performance is remarkably higher than a reference device without BABr that shows a maximum EQE of 2.53% and a brightness of 6190 Cd m−2 at 5 V. The versatility of this method is further extended to another large‐cation ligand, 4‐fluoro‐benzylammonium bromide (F‐BZABr), which leads to maximum EQE of 8.55%. This work indicates two‐step processed mixed 2D/3D perovskites are promising for bright green PeLEDs.

show abstract

Influence of Bulky Organo‐Ammonium Halide Additive Choice on the Flexibility and Efficiency of Perovskite Light‐Emitting Devices

Cited by 91 publications

References 50 publications

Dual Passivation of Perovskite Defects for Light‐Emitting Diodes with External Quantum Efficiency Exceeding 20%

Dual Passivation of Perovskite Defects for Light‐Emitting Diodes with External Quantum Efficiency Exceeding 20%

The Positive Function of Incorporation of Small Molecules into Perovskite Materials for High‐Efficient Stable Solar Cells

Exploiting Two‐Step Processed Mixed 2D/3D Perovskites for Bright Green Light Emitting Diodes

Contact Info

Product

Resources

About