Characterization of Photovoltaic Cells Using n-InN/p-Si Grown by RF-MBE
- PDF / 795,841 Bytes
- 6 Pages / 595 x 842 pts (A4) Page_size
- 23 Downloads / 253 Views
Y10.71.1
Characterization of Photovoltaic Cells Using n-InN/p-Si Grown by RF-MBE Chiharu Morioka1, Tomohiro Yamaguchi1, Hiroyuki Naoi2, Tsutomu Araki1, Akira Suzuki3 and Yasushi Nanishi1 1 Dept. of Photonics, Ritsumeikan Univ., 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577, Japan 2 Center for Promotion of The 21st Century COE Program, Ritsumeikan Univ., 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577, Japan 3 Res. Org. of Sci. & Eng., Ritsumeikan Univ., 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577, Japan
ABSTRACT A newly reported narrow bandgap for indium nitride means that the indium gallium nitride system of alloys can be a candidate for new high efficiency solar cells covering most of the solar spectrum. In this paper, n-InN films were grown on p-Si (100) substrates. We characterize, for the first time, photovoltaic properties using n-InN/p-Si hetero-junction grown by RF-MBE. INTRODUCTION While indium nitride (InN) has a high potential for optical and electronic applications and attracts much attention, growth and characterization as well as device application of InN have not been widely studied, compared with other nitrides. This is because of the difficulty in obtaining high-quality InN due to its low dissociation temperature and high equilibrium vapor pressure. Recently, high-quality InN films with high electron mobility have been obtained on sapphire substrates by techniques such as insertion of low temperature buffer layer and substrate nitridation [1-4]. Using high-quality InN films, the bandgap energy of InN is reported to be less than 1 eV [5-8] rather than the previously accepted value of 1.9 eV [9]. These results enable us to explore new application fields of the group-III nitride semiconductors, which have direct bandgap energies ranging from 0.7 eV (InN) to 6.2 eV (AlN) at room temperature. For example, the indium gallium nitride system of alloys (InxGa1-xN) can be a candidate for new high efficiency solar cells covering most of the solar spectrum. The InxGa1-xN-based solar cells are also expected to be light in weight as well as highly efficient. Unlike GaAs and CdSTe which are currently used as solar cell materials, nitride semiconductor does not contain the toxic elements. As mentioned above, the InxGa1-xN solar cells have many advantages. For the fabrication of InGaN solar cells, InN is suitable to the bottom cell material. Since neither InN bulk crystals nor p-type InN template are available, we employed p-type Si as the substrate.
Y10.71.2
We studied growth of InN on Si (111) substrates and succeeded in realizing single crystalline InN films on Si (111) [10-12]. We also succeeded in observing clear rectifying effect of n-InN/p-Si (111) [13]. In this paper, InN films has been grown on Si (100) substrates. Crystalline structure of the InN films has been investigated. Photovoltaic effect is reported from n-InN/p-Si hetero-junction for the first time. EXPERIMENTAL DETAILS The n-InN/p-Si hetero-junction was formed by growing n-InN films on p-Si (100) substrates using radio-frequency plasma-excited mole
Data Loading...
