Space-charge capacitance of an intrinsic semiconductor film

Abstract

The zero-bias capacitance C of a thin intrinsic semiconductor film sandwiched between identical electron-injecting contacts is computed exactly and compared with the value C0 for noninjecting contacts. The effect of traps and recombination centers is omitted. The curve of normalized capacitance versus film thickness exhibits a bump for an intermediate value of thickness. C/C0 is unity for very thin or very thick films and may reach a maximum value of 1.934 (nominally 2). Contact-dominated conditions disappear for films thicker than four Debye lengths based on the intrinsic carrier concentration. © 1965 The American Institute of Physics.