Resonant Energy Transfer due to Exciton Coupling in Hybrid Persovskites Conjugated to GaN Semiconductors
- PDF / 252,441 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 11 Downloads / 169 Views
0955-I15-07
Resonant Energy Transfer due to Exciton Coupling in Hybrid Persovskites Conjugated to GaN Semiconductors Jianyou Li1, Arup Neogi1, and Teruya Ishihara2 1 Department of Physics, University of North Texas, 211 Ave. A, Denton, TX, 76203 2 RIKEN, Wako, 351-0198, Japan
ABSTRACT Exciton-Exciton coupling in hybrid persovskites conjugated to GaN semiconductors system has been studied. Excitons are strongly coupled in (C6H5C2H4NH3)2PbI4[bis(phenethylammonium)tetraiodoplumbatel] (PEPI) which is a hybrid inorganic-organic layered, with a perovskite structure quantum well (QW). The inorganic PbI4 monolayer is sandwiched between organic layers. The interaction between electron and hole forming the bound exciton is significantly stronger due to dielectric confinement. The lowest exciton binding energy is 220 meV, which is 20 times in comparison to GaAs. Gallium nitride (GaN) semiconductor has defect bound excitons with absorption band, which overlaps with the emission spectra of the PEPI system. This facilitates resonant energy transfer (RET) from the GaN defect bound exciton states to the excitons confined in the PEPI layer. We investigated the interaction by photoluminescence (PL) and found that 1s exciton in the PEPI layer strongly couples with the GaN defect level exciton, which is pronounced at lower temperature (< ~ 100 K). INTRODUCTION The non-radiative energy transfer between quantum confined structure such as colloidal quantum dots (QD) and GaN based quantum wells (QW) has recently been proposed as an approach to enhance the luminescence efficiency with potential application in hybrid light emitting diodes, solar cells and other optoelectronic application [1]. GaN based semiconductors have the distinct advantage of optical transparency, high refractive index, relatively strong exciton binding energy and high nonlinearity compared to conventional III-V semiconductors. However, the size inhomogeneity, surface recombination and exciton bleaching in colloidal QDs affect the carrier transport in this material system for practical optoelectronic applications. Hybrid self-assembled organic-inorganic perovskite films with appropriate optical properties offer an alternative material system to the colloidal QDs. Two-dimensional QWs synthesized with organic-inorganic perovskites such as PbI4 conjugated to phenethylammonium group form highly ordered thin films. These PEPI films exhibit high optical nonlinearity with exciton binding energy 220meV [2]. The PEPI structures therefore exhibit strong room temperature luminescence in the visible region. The PL energy of the perovskite films can be tuned by either changing the width of the lead iodide layer or by modifying the halide group to Br or Cl [3, 4]. This composite on a GaN light emitting semiconductor thereby offers the potential for the development of a white-light emitter. The structure of the PEPI films spin coated on glass substrate investigated by X-ray diffraction exhibit periodic structures. The lead
iodide layer, which forms the QW, has a width of 6.4Å. In
Data Loading...
