Speaker
Ms
Boonyaluk Namnuan
(Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)
Description
$\rm Cu(In,Ga)_3Se_5$ is known as a $\beta$-phase in the phase diagram of $\rm Cu_2$Se and $\rm (In,Ga)_2Se_3$. The existence of this phase on the surface of $\rm Cu(In,Ga)Se_2$ absorber plays an important role for enhancing the performance of $\rm Cu(In,Ga)Se_2$ solar cells. The energy dispersive x-ray spectroscopy (EDX) is used to investigate and confirm the composition of single $\rm Cu(In,Ga)_3Se_5$ film and in order to obtain the deposition conditions. In this study, the $\beta$-$\rm Cu(In,Ga)_3Se_5$ with various thicknesses were deposited after a completion of the three-stage co-evaporation process of $\rm Cu(In,Ga)Se_2$ films. The solar cells with thinner $\rm Cu(In,Ga)_3Se_5$ showed an increase in open-circuit voltage ($V_o$$_c$). The maximum $V_o$$_c$ of 0.707 V was obtained from $\rm Cu(In,Ga)_3Se_5$ film with 10 nm thick. It is noted here that the conversion efficiencies are slightly lower when compared with the standard three-stage growth solar cells without $\rm Cu(In,Ga)_3Se_5$. It is mainly due to a decrease in a short circuit current ($J_s$$_c$) and a fill factor (FF). Based on previous studies, the higher $V_o$$_c$ was obtained by a larger energy band gap caused by valence band offset at the CdS/CIGS interface.
Author
Ms
Boonyaluk Namnuan
(Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)
Co-authors
Dr
Kajornyod Yoodee
(Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)
Dr
Sojiphong Chatraphorn
(Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)
