Hybrid organic–inorganic spin-on-glass CuCl films for optoelectronic applications

Abstract

Cuprous halides are among the most studied inorganic materials for excitonic related linear/non-linear optical processes due to their large excitonic binding energies (∼190 and 108 meV for CuCl and CuBr, respectively). In recent years, we have studied CuCl thin films deposited by vacuum evaporation and sputtering techniques on a variety of substrates. We now report on the extension of this research to the deposition of CuCl nanocrystals on flexible substrates via a spin-on technology. In this study, we present the synthesis, deposition and characterization of CuCl nanocrystals embedded in organic polysilsesquioxane (PSSQ) films on a variety of substrates via the spin coating method. The nanocrystals were synthesized by a complexation–reduction–precipitation mechanism reaction of CuCl2 · 2H2O, alpha D-glucose and de-ionized (DI) water with a PSSQ based solution as the host matrix material. The deposited films were heated at 120 °C for durations between 1 and 24 h in vacuo. The room temperature UV–Vis absorption spectra for all hybrid films, except the as-deposited film, showed both Z1,2 and Z3 excitonic absorption features. Room temperature photoluminescence measurements of all heated films reveal very intense Z3 excitonic emission at 3.221 eV. Room temperature x-ray diffraction (XRD) of the as-deposited films gave no evidence of the crystallization of CuCl. However, after heating the films, XRD confirmed the preferential growth of CuCl nanocrystals whose average size is ≈25–45 nm in the ⟨1 1 1⟩ orientation. The CuCl hybrid films showed bright electroluminescent emission at 384 nm when subjected to an ac voltage of about 100 V peak to peak.

A zero dimensional hybrid organic- inorganic perovskite CuCl4 based: Synthesis, crystal structure, vibrational, optical properties, DFT and TDFT calculations, dielectric properties and biological activity

“…The experimental UV-Vis absorption spectrum superposed with its theoretical homologue is presented in Fig.9. The experimental absorption spectrum of ( [29][30][31][32][33][34][35][36][37]. Worthily, we also reclaim the relatively harmony between experimental and theoretical results, as can be seen in Fig.9.…”

Structural and Optical Properties of Luminescent Copper(I) Chloride Thin Films Deposited by Sequentially Pulsed Chemical Vapour Deposition

“…It has a high exciton binding energy of~190 meV [2], which is higher than both GaN (25 meV) [3] or ZnO (60 meV) [4]. CuCl has been investigated for some time for its application to optoelectronic devices [5][6][7][8]. The high binding energy gives the possibility of stable, room temperature, UV emission which, together with high biexciton binding energies, enables optoelectronic effects such as bistability and four-wave mixing with the potential for new short wavelength devices [9,10].…”

Temperature dependent photoluminescence of nanocrystalline γ-CuCl hybrid films

“…After heating the films, X-ray diffraction (XRD) confirmed the preferential growth of CuCl nanocrystals whose average size is ≈ 35 nm in the 〈111〉 orientation. The details of the solution processes, synthesis and film deposition were described previously [2]. The luminescence properties were studied using temperature dependent photoluminescence spectroscopy in the range between 15 K to room temperature, by employing a UV Ar + Innova laser with a second harmonic generation barium borate crystal producing a 355 nm photoexcitation.…”

“…1 and 2, one can observe a peak occurring at 3.191 eV (≈388.6 nm). This peak is attributed to emission from an exciton bound to an impurity, which has been called the I 1 impurity bound exciton and the impurity or defect involved in this process has been previously identified as a neutral acceptor, possibly a Cu vacancy [2,18]. The peak at 3.170 eV (≈391.2 nm) is identified as a free biexciton M [19].…”

“…CuCl luminescence has been investigated extensively for many years, owing to its interesting structural, optical and electrical properties [1][2][3][4][5][6]. It is an ionic I-VII compound wide direct band gap semiconductor material with the zinc blende structure.…”