This invention relates to photodetector and its array in the form of a image sensor having multispectral detection capability covering the wavelengths from ultra-violet (UV) or near UV to shortwave infrared (over 1700 nm), ultra-violet (UV) or near UV to mid infrared (3500 nm), or ultra-violet (UV) or near UV to 5500 nm. More particularly, this invention is related to the multicolor detector, which can detect the light wavelengths ranges from as low as UV to the wavelengths over 1700 nm covering the most of the communication wavelength, and also from UV to as high as 5500 nm using of the single monolithic detector fabricated on the single wafer. This invention is also related to the multispectral photodetector arrays for multicolor imaging, sensing, and advanced communication. Our innovative approach utilizes surface incident type (either top- or bottom-illuminated type) photodiode structure having single absorption layer and consisting of more than micro-nano-scaled 3-dimensional (3-D) blocks which can provide broader spectral response than that of the absorption layer made from the same type of material having macro-scaled structure.