//Ex:8.25 clc; clear; close; tr=25;// rediative life time in ns tnr=90;// nonrediative life time in ns i=3.5*10^-3;// drive current in amp y=1.31*10^-6;// wavelength in m h=6.625*10^-34;// plank constant c=3*10^8;// the speed of light in m/s e=1.6*10^-19;// charge t=tr*tnr/(tr+tnr);// total carrier recombination lifetime ns ni=t/tr;// internal quantam efficiency pi=(ni*h*c*i)/(e*y);// internal power in watt p_int=pi*10^3;// internal power in mW P=p_int/(ni*(ni+1));// power emitted in mW printf("The total carrier recombination lifetime =%f ns", t); printf("\n The internal quantam efficiency =%f ", ni); printf("\n The internal power =%f mW", p_int); printf("\n The power emitted =%f mW", P);