The energy level and the density of the deep acceptor Fe
3+trap involved in space-charge-limited current (SCLC) flowing in semi-insulating (SI) InP was deduced from

measurements and a model employing either the low-field Hall mobility or the high-field saturated electron velocity υ
s. The modified model based on υ
syields the Fe
3+energy level,

eV, and the trap density

× 10
15cm
3, consistent with data obtained by other means.