I want to deposit CdSe on TiO2(TNT nanotube) by electrochemical deposition methods to improve the absorption of light from the ultraviolet region to the visible and increase photocurrent response (PEC) in order to use it in solar cells
thanks a lot
Photons can not be absorbed if your band gap is higher than the energy of incoming photons. Photo -conductivity will be observed when photon is absorbed and produce electron- hole pair. If you want to get photo conductivity in visible region instead of ultrvoilet region, you have to decrease the band gap of your sample so that it comes in visible range. For solar cell application band should be around 1.5 eV as sun light has maximum intensity at this energy.
How to decrease band gap?. Is there any methods to decrease it ?
Hi,
In order to decrease band gap, you can do doping with metal as well as non metal atoms.
According to you requirement, Please do literature survey on it, definitely you will get.
_Thanks,
Titaniumoxide is widegap material, therefore it absorbes ultraviolet light. In order to absorb more radiation from the solar radiation, one ha to use a narrower gap material
e.g. as you suggested Cd Se. Cd Se has a bandgap of about 1.6 eV that can be modified by the deposited grain size.As the grain size decreases the bandgap increases. So, to absorb more light it may be preferable to increase the grain size. One of the most important things is that the interface states between the two materials must be minimized. This is a conceptual point of view but there is papers treating the propped structure. As an example please follow the Link:web.stanford.edu/.../Solar%20Cells/MATSCI%20316%20Quantum%20D..
wish you success
Hi there,
I completely agree with Dr.Kumar answer, it should the band gap of materials which as photoanode is small enough to enhance the absorb a photon and then produce electron- hole pair, it is commonly see in literature of applications solar cell the band gab is near to 1.5eV as sun light has maximum intensity at this energy.
Regards,
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