Image intensifier using high-sensitivity high-resolution photodetector array

A semiconductor analog photodetector array device contained in a single semiconductor wafer including semiconductor spitaxial layers and having a plurality (>=100) of pixels containing back-illuminated surface-passivated mesa-structure heterojunction-phototransistors (HPTs), wherein both the input optical signal and the output electrical signal are analog instead of digital logic signals, wherein each of the pixels contains at least one heterojunction phototransistor (HPT), wherein said heterojunction phototransistor (HPT) absorbs more than half of the light transmitted into its containing pixel and simultaneously serves as the first-stage amplifier, wherein said heterojunction phototransistor (HPT) forms a mesa structure defined by its surrounding isolation trenches etched into the semiconductor epitaxial layers, wherein said isolation trenches surrounding said mesa significantly reduce electrical crosstalk between said heterojunction phototransistor (HPT) and the rest part of said photodetector array device, wherein all the sidewalls of said heterojunction phototransistor (HPT) mesa are passivated with at least one electrically insulating inorganic passivation material (for example, Al2O3, AIN, Si3N4, SiO2, etc.), and wherein the analog input signal light traverses the semiconductor substrate of said HPT before entering the active layers of said HPT.