AVS 51st International Symposium
    Semiconductors Tuesday Sessions
       Session SC-TuP

Paper SC-TuP9
Electrical Characteristics of Al-doped ZnO (Al-ZnO) Films and their Application to Al-ZnO/p-Si Solar Cells

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: T. Ichinohe, Tokyo National College of Technology, Japan
Authors: T. Ichinohe, Tokyo National College of Technology, Japan
S. Masaki, Tokyo National College of Technology, Japan
K. Kawasaki, TDY Co., Ltd., Japan
Correspondent: Click to Email
We fabricated aluminum doped zinc oxide (Al-ZnO) films by DC-magnetron sputter-deposition. The films showed n-type semiconductor characteristics: they were electron carriers with a negative coefficient of resistivity. We attempted to fabricate a p-n junction structure using Al-ZnO films formed on a p/p@super +@-Si epitaxial substrate. The Al-ZnO/p-Si structure showed rectified I-V characteristics, indicating a p-n junction has been fabricated. The photocurrent for reverse bias increased to several hundred times higher than dark current when a halogen lamp irradiated its surface. The open circuit voltage (V@sub oc@) increased when the halogen lamp power was increased, and the value saturated at about 0.2 V. We infer that the value of V@sub oc@ is appropriate for built-in potential (0.3 eV) in the interface of Al-ZnO/p-Si, as estimated by the Kelvin-probe work function measurement system. Energy efficiency of the Al-ZnO/p-Si structure was about 1.2%, as estimated by the standard quasi-solar light exposure system. Reducing the resistivity of Al-ZnO films and the contact resistance of the cell structure can further increase the energy efficiency.