EVIDENCE OF COHERENT QUANTUM 1 F NOISE IN LONG N+P DIFFUSION CURRENT DOMINATED (HG,CD)TE PHOTODIODES/

The 1/f fluctuations of dark-current- and photocurrent-induced noise i n implanted n+ p Hg0.5Cd0.5Te photodiodes are analyzed within the diff usion-current-dominated bias region at 300 K. The lifetime of the elec trons in the p-type region has been determined experimentally. Therefo re, the Hooge parameter a(H) is well defined by the 1/f noise spectrum . The a(H) value, calculated from dark-current-induced 1/f noise, is i n close agreement with the result of Handel's coherent state 1/f-noise theory, which yields a(H)=4.6 x 10(-3). The 1/f noise of the photoind uced current without applied bias can be described with the same a(H) value. These results indicate coherent state quantum 1/f noise generat ed by dark current as well as photoinduced current as a result of mobi lity fluctuations. If both independent types of currents are generated in the photodiode, the resulting 1/f noise can be sufficiently descri bed only within the concept of coherent state quantum 1/f noise.