http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
( Tharith Sriv ),( Thi M. H. Nguyen ),( Van Q. Nguyen ),조성래,정현식 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1
Earth abundant, low-cost & low-toxic p-type semiconductor materials such as SnS(e) have gained interests in photovoltaic applications due to high optical absorption coefficient & great electrical properties. In this study, we report polarized Raman results of anisotropic SnSe<sub>(1-x)</sub>S<sub>x</sub> (0≤x≤1), where six excitation energies were used. First, we show that like SnS(e) where several A<sub>g</sub> & B<sub>3g</sub> modes are observed in backscattering geometry, several SnS(e)-like A<sub>g</sub> & B<sub>3g</sub> are observed in parallel & cross polarization configurations in the materials of 0<x<1. Each observed A<sub>g</sub> & B<sub>3g</sub> modes agree well with group theory analysis to exhibit interesting anisotropic properties with two- & four-fold symmetry for A<sub>g</sub> & B<sub>3g</sub>, respectively. Secondly, insights into excitation energy and polarization dependences of Raman spectra are demonstrated. Finally, one- & two-mode behaviors being observed in the alloys are discussed.
Observation of ZnO secondary phase in CZTSe solar cell
임수연,( Tharith Sriv ),오지아,전찬욱,정현식 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1
Raman spectroscopy is a powerful tool to detect secondary phases in Cu<sub>2</sub>ZnSnSe<sub>4</sub> (CZTSe) solar cells without destruction of the samples. It is possible to detect a small amount of secondary phases in CZTSe by using the resonance Raman effect. Since the secondary phases can lead to unexpected behavior in CZTSe solar cell and a small amount of the secondary phases can cause a performance drop in solar cell devices, identifying secondary phases is important. We carried out resonance Raman spectroscopy with four lasers with excitation energies of 1.96 eV, 2.41 eV, 2.81 eV, and 3.82 eV, which are similar to the bandgap of common secondary phases such as SnSe2, SnSe and ZnSe. We observed unusual ZnO as a secondary phase in our dimpled CZTSe absorber layer. Although ZnO is usually used as n-type TCO layer in CZTSe solar cell, a ZnO layer was not initially deposited on our absorber layer. Additionally, we found that ZnO can be formed when high power UV laser is irradiated on CZTSe.
Observation of unexpected secondary phases in CZTSe solar cell using Raman spectroscopy
임수연,( Tharith Sriv ),오지아,김삼미,김세윤,양기정,강진규,김대환,전찬욱,정현식 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-
Raman spectroscopy is a widely used tool to detect secondary phases in Cu<sub>2</sub>ZnSnSSe<sub>4</sub> (CZTSSe) solar cells without damaging samples. Since a small amount of the secondary phases can cause a performance drop in CZTS/Se solar cell devices, identifying secondary phases is important. Since Raman signals are highly sensitive to the existence of secondary phases using the resonance Raman effect, it is possible to detect a small amount of secondary phases in the solar cell. We carried out Raman spectroscopy with four lasers as excitation energies. We observed unusual secondary phases, ZnO and S/Se alloy in our CZTSSe absorber layer. ZnO is usually used as an n-type TCO layer in CZTSe solar cells, but a ZnO layer was not initially deposited on our absorber layer. Additionally, we found that ZnO can be formed when high power UV laser is irradiated on CZTSe. For S/Se alloy, we compared Raman signals from S/Se alloy clusters to S and Se powders.
오지아,송유진,임수연,Tharith Sriv,정현식,전찬욱 한국물리학회 2020 Current Applied Physics Vol.20 No.8
A Cu2ZnSnSe4 (CZTSe) photovoltaic absorber thin films were prepared using a 2-step selenization process on a Ti substrate including a Na precursor layer and a Na-free Ti substrate, and the effect of Na on the solar cell performance was compared. A CZTSe flexible solar cell fabricated on a Ti foil substrate exhibited an efficiency of 3.06%, which was less than half that of a solar cell fabricated on a soda lime glass substrate. This was attributed to the absence of Na and severe Zn crowding near the back contact. By depositing a 100‐nm-thick sodalime glass thin film on a Ti substrate to supply Na, the efficiency increased up to 5.59%. In the Na-doped CZTSe absorber layer grown on the Ti substrate, the back crowding of Zn was eliminated and the upper part of the absorption layer was converted to a Zn-rich environment, which prevented the formation of CuZn antisite defects.