  Understanding broadband photoconductive behaviour in two dimensional layered
materials are important in order to utilize them for a variety of
opto-electronic applications. Here we present our results of photocurrent
spectroscopy measurements performed on few layer Indium Selenide (InSe) flakes.
Temperature (T) dependent (40 K < T < 300 K) photocurrent spectroscopy was
performed in order to estimate the band-gap energies E_g(T) of InSe at various
temperatures. Our measurements indicate that room temperature E_g value for
InSe flake was ~ 1.254 eV, which increased to a value of ~ 1.275 eV at low
temperatures. The estimation of Debye temperatures by analysing the observed
experimental variation of E_g as a function of T using several theoretical
models is presented and discussed.
