| dc.description.abstract | The production of silicon solar cells can use many methods, commonly used high-temperature diffusion and ion implantation to form a PN junction. The activation temperature of dopant is above 900oC for high-temperature diffusion and ion implantation methods, it will consume much energy of these manufacture technologies. In this thesis for the fabrication technology of c-Si solar cells, we can grow epitaxial-like silicon thin films with dopants at low temperatures (<200oC) by ECRCVD. It will diminish issues of energy consumption, as compared with the traditional high-temperature diffusion process.
For the study of epitaxial-like silicon thin films with dopants, we modulate the recipes of ECRCVD, such as microwave power, working pressure, dilution ratio of process gas, and thickness to investigate their structural and electronic characteristics. The thickness and crystalline fraction of the boron-doped thin films were measured by spectroscopic ellipsometry (SE), and their electrical properties such as mobility, concentration, and resistivity were measured by Hall effect measurement. Under the condition of low microwave power and high working pressure, the carrier concentration, and resistivity of a boron-doped epitaxial-like Si thin film with 7 nm thickness is 1.6x1019(cm-3), and 6.7x10-3(Ω-cm), the crystallinity is about 79%. Furthermore, we can control the carrier concentration varied between 2.2x1017 and 2.3x1020(cm-3) under the modulation of process gas dilution ratio.
The c-Si solar cell was fabricated with the structure : ITO / epi-Si:H (p+) / c-Si(n) / μc-Si:H (n+). Doped with a high carrier concentration and a low resistivity of the thin thickness that will reduce the solar light incident on the front of the absorption. The low electrical properties of silicon thin film solar cells can be reduced series resistance, and doped silicon thin films with different silicon solar cell research in the photoelectric conversion characteristics. We modulate the doping gas ratio, microwave power, and working pressure to obtain various carrier concentrations of emitter thin films. When the carrier concentration is above 8x1019 cm-3, the 560 mV of Voc and 35 mA/cm2 of Jsc can be achieved in the performance of solar cells.
Therefore, this study can be in the plane n-type FZ (100) silicon substrate optimum solar cell characteristics: Voc = 560.4mV, Jsc = 37.69 mA/cm2, FF = 73.3%, finally resulting in the efficiency of solar source AM1.5 in 1 cm2 area was 16.23%. | en_US |