서지주요정보
$Cu_2Te$ 배면전극을 이용한 CdTe 태양전지의 광전압 특성 및 안정성에 관한 연구 = A study on the photovoltaic properties and stability of CdTe solar cells with $Cu_2Te$
서명 / 저자 $Cu_2Te$ 배면전극을 이용한 CdTe 태양전지의 광전압 특성 및 안정성에 관한 연구 = A study on the photovoltaic properties and stability of CdTe solar cells with $Cu_2Te$ / 김기환.
저자명 김기환 ; Kim, Ki-Hwan
발행사항 [대전 : 한국과학기술원, 2002].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8012901

소장위치/청구기호

학술문화관(문화관) 보존서고

MMS 02010

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

CdTe solar cells are leading candidate for cost-effective photovoltaics due to near-optimum band gap og 1.4eV, high absorption coefficient, and low cos manufacturability. However, CdTe has a large work function to form a schottky contact with metal electrode instead of ohmic contact. To achieve a high and stable efficiency for the CdS/CdTe solar cells, the formation of ohmic contact to p-type CdTe film is essential. In search of a new ohmic contact material, this thesis proposes $Cu_2Te$ because it can be a Cu source for p+ tunneling ohmic contact and be a metallic electrode with a good lattice match to CdTe. In this work, CdS films were prepared by a chemical bath deposition (CBD) method on ITO/glass substrate. CdTe films were deposited on CdS/ITO/glass substrate by a close spaced sublimation (CSS) method with screen printed CdTe layer as a source at the source temperature of 650 ℃ and at the substrate temperature of 590 ℃. These films were annealed at 400 ℃ with $CdCl_2$ powder on the CdTe film. A $Cu_2Te$ layer was deposited oc the CdTe film by evaporating $Cu_2Te$ powder. Then the samples were annealed at 100, 150, 200 and 250 ℃ for 5 min to for p+ ohmic contact. Au was deposited on the $Cu_2Te$ and annealed at 100℃ for secondary electrode. Transmission electron microscope (TEM) analysis showed that an amorphous layer with a thickness of about 2 nm was formed at the CdTe/$Cu_2Te$ interface. As the $Cu_2Te$ annealing temperature increased, the thickness of amorphous layer was decreased. And the amorphous layer was completely crystallized when the annealing temperature was 200 ℃. X-ray diffraction (XRD) analysis showed that both the hexagonal and orthorhombic $Cu_2Te$ was formed in as - deposited. But more hexagonal $Cu_2Te$ was grown at and above 200 ℃ annealing. From the TEM images and XRD patterns, we think that the orthorhombic $Cu_2Te$ phase near the CdTe interface was transformed into the hexagonal $Cu_2Te$ by the good lattice match between $Cu_2Te$ (0001) plane and CdTe (111) planes. A good p+ ohmic contact was achieved when the annealing temperature was between 180 ℃ to 200 ℃. The series resistance of the CdS/CdTe cell was reduced to $0.5 Ω·cm^2$. Best cell efficiency of 10.9% was obtained when post annealing temperature was 200℃ for 5 min. Thermal aging test of the CdS/CdTe cells with carbon back contact showed that the $Cu_2Te$ contact was stable at 50 ℃ in $N_2$ and was slowly degraded at 100 ℃ in $N_2$. In comparison to the conventional carbon contact, the $Cu_2Te$ contact showed a better thermal stability.

서지기타정보

서지기타정보
청구기호 {MMS 02010
형태사항 iii, 82 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Ki-Hwan Kim
지도교수의 한글표기 : 안병태
지도교수의 영문표기 : Byung-Tae Ahn
학위논문 학위논문(석사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 79-82
주제 $Cu_2Te$
태양전지
카드뮴
카퍼
텔러라이드
$Cu_2Te$
CdTe
solar celll
cupper
teleride
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