In this paper we present the increased light emission for Si p-i-n light emitting diodes (LEDs) by geometrical scaling of the injector size for p- and n- type carriers. Simulations and electrical and optical characteristics of our realized devices support our findings. Reducing the injector size decreases the leakage of minority carriers in the injector regions, availing more carriers for effective radiative recombination in the intrinsic volume of the device. A comparison is made between reference large-scale and nano-size injector p-i-n diodes. (c) 2012 Elsevier Ltd. All rights reserved.