How to perform integration of product of multiple function inside a for loop?

Hello everyone, I am having some troube integrating insiide a for loop. I am providing the code below. The code works wiithout the integration part when is not inside a loop. I am having Undefined operator '*' for input arguments of type 'function_handle' error. Can anyone fix my problem. It will be a great help and learning opportunity.

clc
clear all
close all


Fs= 2.16*10^-5*pi;            % Geometrical Factor for sun
h= 4.136*10^-15;              % Plancks Constant
c= 3*10^8;                    % Speed of light
k = 8.6173*10^-5;             % Boltzmanns Constant
Ts=5760;                      % Temparature of the sun
q=1.6*10^-19;                 % electronic charge
T=300;                        % ambient temparature

beta=7.021*10^-4;
gamma=1108;
Eg0_1=1.1557;
Eg0_2=2.5;
Egd0=3.2;

Eg1=Eg0_1-((beta*(T^2))/(T+gamma));
Eg2=Eg0_2-((beta*(T^2))/(T+gamma));
Egd=Egd0-((beta*(T^2))/(T+gamma));

Ep1=1.827*10^-2;
Ep2=5.773*10^-2;
C1=5.5;
C2=4.0;
A1=3.231*10^2;
A2=7.237*10^3;
Ad=1.052*10^6;
A=((2*Fs)/((h^3)*(c^2)));

lambda_min=200*10^-9;
lambda_max= 1200*10^-9;


depth=0.1:0.01:5;
num=numel(depth);
G_t=nan(1,num);


for a=1:num
    
    x=depth(a);

    Photon_flux=@(lambda)((A*((((h*c)/lambda)^2)/(exp((((h*c)/lambda)/(k*Ts)))-1)))*q);
    Alpha= @(lambda)((((C1*A1)*(((((h*c)/lambda)-Eg1+Ep1)^2)/(exp(Ep1/(k*T))-1)))+((C1*A1)*(((((h*c)/lambda)-Eg1-Ep1)^2)/(1-exp(-Ep1/(k*T)))))+(Ad*((((h*c)/lambda)-Egd)^(1/2))))*(10^-4));
    Generation_Rate=@(lambda)(Photon_flux*Alpha*exp(-Alpha*x));
    
    G_t(a)=integral(Generation_Rate,lambda_min,lambda_max);
    
end

plot(depth,G_t)
xlabel('depth \microm'),ylabel('Total Generation Rate')

Answer 1

[Torsten]

for a=1:num
    
    x=depth(a);
    Photon_flux=@(lambda)((A*((((h*c)/lambda)^2)/(exp((((h*c)/lambda)/(k*Ts)))-1)))*q);
    Alpha= @(lambda)((((C1*A1)*(((((h*c)/lambda)-Eg1+Ep1)^2)/(exp(Ep1/(k*T))-1)))+((C1*A1)*(((((h*c)/lambda)-Eg1-Ep1)^2)/(1-exp(-Ep1/(k*T)))))+(Ad*((((h*c)/lambda)-Egd)^(1/2))))*(10^-4));
    Generation_Rate=@(lambda)(Photon_flux(lambda)*Alpha(lambda)*exp(-Alpha(lambda)*x));
    
    G_t(a)=integral(Generation_Rate,lambda_min,lambda_max,'ArrayValued',true);
    
end