Improvement of electroluminescence characteristics of porous silicon LED by using amorphous silicon layers

Amorphous silicon (a-Si:H) layers are used to improve the injection current density J and threshold voltage Vth of porous-silicon light-emitting diodes (PS-LEDs). A PS-LED with n-i-n-p-n a-Si:H layers is shown to have a substantially (> 6 orders of magnitude) higher J than that of the PS-LED without any a-Si:H layers. In addition, a lower Vth of 4.2 V and a higher brightness B of 20.5 cd/m2 at J = 600 mA/cm2 are achieved as compared to other PS-LEDs with n-i-p-n a-Si:H layers.