Hello Ankit,

You must have incident intensity (Watt/m^2), where

External Quantum Efficiency (EQE): is the ratio of number of charge carriers collected by cell to the number of incident photons of a given energy

 EQE= (electrons⁄sec)/(photons⁄sec)=(current⁄(electron charge))/((light power)⁄(energy of 1 photon))

or in units EQE= ((I_sc (A=coulomb/sec))⁄(1.6×〖10〗^(-19) (colume)))/((P_in (Watt=Joule/sec))⁄((1eV=1.6×〖10〗^(-19) J)))=(electron⁄sec)/(photon⁄sec)

EQE give us responsitivity of solar cell device for different wavelengths when it supplied for solar radiation.

To fined EQE , we need Is.c (Amper) and Pin (Watt), we must Pin =I(watt/m2)×A(m2) to get on the power in watt unit.

IQE=EQE/A(absorbance)

This could be helpful

http://surface.syr.edu/cgi/viewcontent.cgi?article=1136&context=phy_etd

Bilal Yaseen Taher May I ask why we use I_sc instead of I_mp(current corresponding to the maximum power)?