Light emission enhancement by geometrical scaling of carrier injectors in Si-based LEDs

In this paper we present the increased light emission for Si p-i-n light emitting diodes (LED) by geometrical scaling of the injector size for p- and n-type carriers. TCAD simulations and electrical and optical characteristics of our realized devices support our findings. Reducing the injector size decreases the diffusion current: therefore, for a particular on current, the pn-product, and hence the radiative recombination, inside the active region increases. A comparison is made among reference large-scale, micro-size and nano-size injector p-i-n diodes. We demonstrate a 4-fold increase in electroluminescence (EL) when the injectors are scaled down to micro-size and a further 10-fold increase for nano-size injectors.