in the size of each photodiode will affect the resolution of the resulting array furthermore if the blocking diode is made too large relative to the photodiode excess capacitance may be added to the circuit which capacitance will be detrimental to the operation thereof consequently it has been found desirable to have the photodiode cover an area which is at least five times and preferably ten times greater than the area of the blocking diode fig6 shows that the photosensitive pixel 10 may be formed on an insulating substrate 56 which substrate is preferably corning 7059 glass but may be formed from any other suitable material such as stainless steel coated with an insulating layer formed on top of substrate 56 is a bottom metal layer 58 which may be chromium said layer 58 subsequently photolithographically patterned using conventional techniques to form a patterned metallic layer under each photosensitive pixel 10 and to simultaneously form input line 44 and output lines 46 the patterned metal layer 58 forms the conductive bases 50 and 52 which bases respectively serve as one of the electrodes for the diodes 16 and 18 they metal layer 58 also forms conductive connector 54 interconnecting the two bases next layers of n i p semiconductor alloy material 60 are deposited upon bases 50 and 52 so as to form the photogenerative portions of diodes 16 and 18 placed over each of the layers 60 is a discrete top contact 62 said top contact preferably being made from transparent conductive oxides such as idium tin oxide ito an insulating layer 64 is then deposited and patterned in order to insulate conductive.