Enhanced chromaticity of organic electroluminescence from silicon-based organic microcavity
电致发光色纯性增强的硅基有机微腔

Electroluminescence (EL) from Si-based organic microcavity has firstly been reported in the literature. The microcavity is made up of the central active multilayers sandwiched between a silver film and a porous silicon Bragg reflector (PS-DBR), formed by electrochemical etching of p +-Si substrate in the electrolyte of HF: C 2H 5OH:H 2O. The central active multilayers consist of Al (1 nm) / LiF (0 5 nm) / Alq 3 / Alq 3: DCJTB / NPB / CuPc / ITO / SiO 2. The reflectivity (relative to an Al mirror) of the PS-DBR is up to 99%, and the stopband is about 160 nm wide. Resonant cavity mode appears as a tip in the reflectivity spectrum of the Si-based organic multilayer films, indicating that the Si-based organic multilayer structure is indeed a microcavity. The peak widths of the EL spetra are greatly reduced from 70 nm to 12 nm as compared with those measured from non-cavity structures. Note that the EL emission from the cavity devices is single-mode, and the off-resonant optical modes are highly suppressed. Moreover, an increase of a factor of about 4 of the resonant peak intensity is observed. In addition, the current-brightness-voltage characteristics and the effect of parameters on the lifetime of the cavity devices are also discussed. The present technique for obtaining enhanced EL emission from Si-based organic microcavity may also be another novel effective method for realizing all-Si-based photonic devices and optoelectronics device integration.