Hi. I'm looking at quantum wells in solar cells. I'm not clear on how they actually work. In the scenario where we have GaInAs wells with the bulk material being GaAs how exactly does the solar cell operate? The way I view it is that the depletion region extends over all the quantum wells so that when we get a photo generated electron-hole pair then the electron is swept by the field and contributes to the photocurrent. Is this correct? If so does the bulk region also contribute to photocurrent? And why is the bulk material refered to as barriers? Any help would be awesome. Thanks.