Title :
Wide bandgap thin film solar cells from CdTe alloys
Author :
Rohatgi, A. ; Sudharsanan, R. ; Ringel, S.A. ; Meyers, P.V. ; Liu, C.H.
Author_Institution :
Sch. of Electr. Eng., Georgia Inst. of Technol., Atlanta, GA, USA
Abstract :
The growing of ternary films of CdZnTe and CdMnTe by molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD), respectively, on glass/SnO2/CdS substrates with a target bandgap of 1.7 to 1.8 eV for solar cell applications is presented. X-ray diffraction, surface photovoltage spectroscopy, and Auger electron spectroscopy measurements were performed to estimate the bandgap, compositional uniformity, and interface quality of the films. Front-wall CdTe cell (glass/SnO2/CdS/CdTe/ZnTe/metal) efficiencies were found to be approximately 9%, while CdZnTe and CdMnTe efficiencies were approximately 3.6% and 6%, respectively. The n-i-p cell efficiencies were consistently higher than those of the n-p cells. The optimum cell processing temperature for CdZnTe films was found to be less than 400 degrees C. Higher processing temperatures caused a shift in bandgap coupled with film quality degradation.
Keywords :
Auger effect; CVD coatings; X-ray diffraction examination of materials; cadmium compounds; energy gap; manganese compounds; molecular beam epitaxial growth; semiconductor growth; solar cells; ternary semiconductors; zinc compounds; 3.6 percent; 6 percent; 9 percent; Auger electron spectroscopy measurements; CdMnTe solar cells; CdTe; CdZnTe solar cells; X-ray diffraction; compositional uniformity; film quality degradation; interface quality; metalorganic chemical vapor deposition; molecular beam epitaxy; n-i-p cell; n-p cells; semiconductor; surface photovoltage spectroscopy; ternary films; wide bandgap thin film solar cells; Chemical vapor deposition; Glass; MOCVD; Molecular beam epitaxial growth; Photonic band gap; Photovoltaic cells; Spectroscopy; Substrates; Temperature; Transistors;
Conference_Titel :
Photovoltaic Specialists Conference, 1988., Conference Record of the Twentieth IEEE
Conference_Location :
Las Vegas, NV, USA
DOI :
10.1109/PVSC.1988.105955
