Silicon PIN photodiode array for medical applications: structure, optical properties and temperature coefficients

The properties of back-illuminated PIN photodiode arrays built on thin silicon wafers are discussed. The arrays are characterized with the high quantum efficiency (~100%), fast signal rise/fall time, and very small crosstalk (<0.01%) within the spectral range from 400 through 800 nm. The crosstalk remained well below 0.01% even when the illuminated cell was floating. Such exciting crosstalks properties of the back-illuminated photodiode arrays allow for building imaging systems with improved noise characteristics and detectivity that is important for the prospective practical applications. The paper discusses also temperature characteristics of the arrays: the shunt resistance temperature coefficient was typically below 10%/C and the responsivity temperature coefficient value did not exceed +0.02%/C within the spectral range from 500 through 700 nm