TY - GEN
T1 - Study on the nano-crystalline Si embedded ZnO thin films for solar cell application
AU - Kuo, Kuang Yang
AU - Hsu, Shu Wei
AU - Chuang, Wen Ling
AU - Lee, Po-Tsung
PY - 2011
Y1 - 2011
N2 - The characteristics of nano-crystalline silicon (nc-Si) embedded in Si-based dielectric matrix have been investigated extensively. However, these Si-based dielectric materials have the highly-resistive nature and difficulty in building up the built-in electric field, which limit the performances of nc-Si thin films for solar cell (SC) application. In this study, we propose to use ZnO as a new matrix material for the nc-Si thin films with better optoelectronic properties because of the unique characteristics of ZnO. We successfully demonstrate the formation of nc-Si embedded in ZnO thin films using a ZnO/Si multilayer (ML) structure by radio-frequency (RF) magnetron sputtering method. From the high-resolution transmission electron microscope (HRTEM) images, we clearly observe the amorphous Si (a-Si) nano-clusters after deposition and high density of nano-crystalline clusters after annealing in the ZnO/Si ML structure. From atomic force microscope (AFM) images, significant variations on the surface morphologies are observed under different Si sputtering powers (P Si) after deposition. The larger surface roughness and clearer formation of a-Si nano-clusters are observed for P Si higher than 75 W. Combined with the Raman spectra and X-ray diffraction patterns, the results indicate that the sputtered Si atoms with higher P Si have more kinetic energy to aggregate together and are easier to form a-Si nano-clusters during deposition. Such morphology is helpful for the nc-Si formation and the better crystallization of the ZnO matrix during annealing. Thus, high density of nano-crystalline clusters is observed in the HRTEM images after annealing. Our experimental results show the nc-Si embedded ZnO thin film is certainly achievable, and a high conversion efficiency SC integrating nc-Si thin film with ZnO matrix can be expected.
AB - The characteristics of nano-crystalline silicon (nc-Si) embedded in Si-based dielectric matrix have been investigated extensively. However, these Si-based dielectric materials have the highly-resistive nature and difficulty in building up the built-in electric field, which limit the performances of nc-Si thin films for solar cell (SC) application. In this study, we propose to use ZnO as a new matrix material for the nc-Si thin films with better optoelectronic properties because of the unique characteristics of ZnO. We successfully demonstrate the formation of nc-Si embedded in ZnO thin films using a ZnO/Si multilayer (ML) structure by radio-frequency (RF) magnetron sputtering method. From the high-resolution transmission electron microscope (HRTEM) images, we clearly observe the amorphous Si (a-Si) nano-clusters after deposition and high density of nano-crystalline clusters after annealing in the ZnO/Si ML structure. From atomic force microscope (AFM) images, significant variations on the surface morphologies are observed under different Si sputtering powers (P Si) after deposition. The larger surface roughness and clearer formation of a-Si nano-clusters are observed for P Si higher than 75 W. Combined with the Raman spectra and X-ray diffraction patterns, the results indicate that the sputtered Si atoms with higher P Si have more kinetic energy to aggregate together and are easier to form a-Si nano-clusters during deposition. Such morphology is helpful for the nc-Si formation and the better crystallization of the ZnO matrix during annealing. Thus, high density of nano-crystalline clusters is observed in the HRTEM images after annealing. Our experimental results show the nc-Si embedded ZnO thin film is certainly achievable, and a high conversion efficiency SC integrating nc-Si thin film with ZnO matrix can be expected.
UR - http://www.scopus.com/inward/record.url?scp=84861048536&partnerID=8YFLogxK
U2 - 10.1109/PVSC.2011.6186578
DO - 10.1109/PVSC.2011.6186578
M3 - Conference contribution
AN - SCOPUS:84861048536
SN - 9781424499656
T3 - Conference Record of the IEEE Photovoltaic Specialists Conference
SP - 3011
EP - 3014
BT - Program - 37th IEEE Photovoltaic Specialists Conference, PVSC 2011
T2 - 37th IEEE Photovoltaic Specialists Conference, PVSC 2011
Y2 - 19 June 2011 through 24 June 2011
ER -