Lasing from Laminated Quasi‐2D/3D Perovskite Planar Heterostructures

Abstract

Planar heterostructures are widely used in commercial III-V semiconductor lasers, but not yet explored for perovskite gain media. This study investigates the gain performance of a CsPbBr 3 (BABr) x /CsPbBr 3 (quasi-2D/3D) perovskite planar heterostructure fabricated by lamination. The resulting heterostructure is designed to enhance the photon and excited-state density in a nonquantum-confined thin 3D layer (30 nm) by simultaneously 1) confining the optical mode and 2) supporting excited-state transfer from the wider-bandgap quasi-2D perovskite to the lower-bandgap 3D perovskite. This allows the low amplified spontaneous emission (ASE) threshold of 150 (±20) µJ cm −2 and lasing threshold of 46 (±15) µJ cm −2 to be realized in such a heterostructure under nanosecond pumping. Further modeling reveals that the ASE performance can be significantly improved via maximizing the excited-state transfer efficiency (only 14% for current prototypes) and highlights the potential of perovskite planar heterostructures as high-performance gain media.

All-printed SU8-perovskite DFB laser

“…Once the SU8 has been printed and cured, the perovskite dissolved in 3:1 (vol.\%) N,N-dimethylformamide (DMF):dimethyl sulfoxide (DMSO) with a concentration of 0.65 M is spin-coated onto the grating and annealed at 100°C for 1h to obtain a thin film of approximately 180 nm. [4].…”

Enhancement of Amplified Spontaneous Emission by Electric Field in CsPbBr3 Perovskites

“…These employ a smooth CsPbBr 3 emissive layer fabricated through the previously reported process of annealing a quasi-2D precursor film at a high temperature. 37,38 The excited-state population in this layer is known to be dominated by free charge carriers, and this is beneficial for its gain performance. 37,38 It is sandwiched between a ZnO electron transporting layer (ETL) and a poly[ (9,9- hole transporting layer (HTL).…”

“…37,38 The excited-state population in this layer is known to be dominated by free charge carriers, and this is beneficial for its gain performance. 37,38 It is sandwiched between a ZnO electron transporting layer (ETL) and a poly[ (9,9- hole transporting layer (HTL). Integrating a CsPbBr 3 film into an LED device significantly reduces its ASE performance due to the worse optical confinement in CsPbBr 3 layer caused by the change in the dielectric environment (Figure S1a,b).…”

“…We first develop perovskite LED devices whose device architecture is tuned to minimize the optically pumped ASE threshold. These employ a smooth CsPbBr 3 emissive layer fabricated through the previously reported process of annealing a quasi-2D precursor film at a high temperature. , The excited-state population in this layer is known to be dominated by free charge carriers, and this is beneficial for its gain performance. , It is sandwiched between a ZnO electron transporting layer (ETL) and a poly­[(9,9-dioctylfluorenyl-2,7-diyl)- co -(4,4′-( N -(4-sec-butyl-phenyl)­diphenylamine) (TFB) hole transporting layer (HTL). Integrating a CsPbBr 3 film into an LED device significantly reduces its ASE performance due to the worse optical confinement in CsPbBr 3 layer caused by the change in the dielectric environment (Figure S1a,b).…”

Ultra-Efficient Optical Gain and Lasing in MDACl2-Doped Perovskite Thin Films

“…Solution-processed organometallic halide perovskites (CH 3 NH 3 PbX 3 , where X = Cl, Br, I) have been widely explored and deciphered for various optoelectronic applications because they exhibit excellent wavelength tunability, high absorption/emission efficiency, and easy and low fabrication cost. − Optically pumped amplified stimulated emission (ASE) and lasing have been demonstrated in a variety of gain media such as 3D, 2D, 1D, and 0D perovskites − and in a number of cavity configurations, including distributed feedback structures, , vertical cavity surface emitter , and whispering-gallery mode , configurations. Despite these advances, solution-processed, cavity-free perovskite thin films generally demonstrate lasing with relatively high thresholds and moderate gain values. ,,,− The optical gain and ASE properties of the materials deteriorate because of the optical losses from scattering and non-radiative recombination, which originate mainly from the defect states at the surface/bulk of the perovskite materials and their irregular morphology due to grain boundaries and sample inhomogeneity. ,,, …”