상세정보
학술지
Ultrafast Photoexcited-Carrier Behavior Induced by Hydrogen Ion Irradiation of a Cu(In,Ga)Se2 Thin Film in the Terahertz Region
- 발행일
- 202103
- 출처
- IEEE Transactions on Terahertz Science and Technology, v.11 no.2, pp.175-182
- ISSN
- 2156-342X
- 출판사
- IEEE
- 협약과제
- 20JB1900, 무독성 버퍼층을 갖는 다색 플렉서블 박막 태양전지 기술 개발, 정용덕
- 초록
- We investigated the effects of H+ ion irradiation on a chalcogenide Cu(In,Ga)Se2 (CIGS) thin film as a function of the dose concentration (1014 ~ 1016/cm2) at 200 keV by using time-resolved THz spectroscopy. The optical conductivity of these films was derived from THz time-domain spectroscopy (THz-TDS) in the THz region. THz emission spectroscopy revealed the emission of a strong-intensity THz pulse from the H+ ion-irradiated CIGS thin film. This is explained by considering the ultrafast behavior of photocarriers, resulting in strong surface band bending induced by the built-in potential with a conversion of the CIGS thin film from p-to n-type. Finally, we used optical pump THz probe spectroscopy to examine the ultrafast photocarrier dynamics determined by the time of capture at the increased number of surface and bulk defect states. This clearly showed that irradiation with H+ ions could generate a number of defect states while simultaneously pacifying the Cu vacancy defects.
- KSP 제안 키워드
- Built-in potential, Bulk defect, CIGS thin films, Hydrogen ion, Ion irradiation, N-type, Optical conductivity, Surface and bulk, THz emission, THz time-domain spectroscopy(THz-TDS), Terahertz region