A nondestructive method to determine the diffusion length of minority carriers in ap‐silicon wafer is outlined. This novel method is based on creating an accumulation layer on one side and an inversion layer on the other side of the wafer by depositing thin semitransparent layers of high (e.g., palladium) and low (e.g., aluminum) workfunction metals, respectively. The wafer acquires a structure akin top+‐p‐n+and is capable of generating a photocurrent when illuminated. The photocurrentIsc(where sc represents short circuit) as a function of the intensityPinof a monochromatic radiation incident on the accumulation layer (p+) side of the wafer is measured. The diffusion lengthLis determined from the slope of theJscvsPincurve. The values ofLso determined were compared with that determined from the measurement of spectral response by illuminating the wafer from the inversion layer (n+) side and were found to be in excellent agreement.