Hydrogenated Amorphous Silicon Oxide Solar Cells Fabricated near the Phase Transition between Amorphous and Microcrystalline Structures

We investigated the properties of hydrogenated amorphous silicon oxide (a-Si1-xOx:H) deposited near the phase transition between amorphous and microcrystalline structures. a-Si1-xOx:H films were prepared by plasma-enhanced chemical vapor deposition using a gas mixture of silane, hydrogen, and carbon dioxide. The film structure was changed from amorphous to microcrystalline phase by increasing hydrogen dilution. Optical and electrical characterizations revealed that wide-gap a-Si1-xOx:H films were deposited under phase transition conditions. We also fabricated a-Si1-xOx:H single-junction p–i–n solar cells by varying the hydrogen dilution for the i-layer. The solar cells showed a maximum open circuit voltage of 1.04 V (Jsc=7.92 mA/cm2, FF=0.64, Eff=5.2%) when the i-layer was deposited under phase transition conditions.

[1]  Kenji Yamamoto,et al.  Wide Optical-Gap a-Si:O:H Films Prepared from SiH4–CO2 Gas Mixture , 1986 .

[2]  M. Konagai,et al.  Low-temperature Deposition of Hydrogenated Microcrystalline Silicon Thin Films by Photochemical Vapor Deposition Technique and Their Application to Thin Film Solar Cells , 2007 .

[3]  M. Konagai,et al.  Optimization of Amorphous Silicon Oxide Buffer Layer for High-Efficiency p-Type Hydrogenated Microcrystalline Silicon Oxide/n-Type Crystalline Silicon Heterojunction Solar Cells , 2008 .

[4]  W. W. Wenas,et al.  Optimization of ZnO Films for Amorphous Silicon Solar Cells , 1993 .

[5]  N. A. Bakr,et al.  Influence of hydrogen dilution on structural, electrical and optical properties of hydrogenated nanocrystalline silicon (nc-Si:H) thin films prepared by plasma enhanced chemical vapour deposition (PE-CVD) , 2008 .

[6]  Wolodymyr Czubatyj,et al.  Oxygen-bonding environments in glow-discharge-deposited amorphous silicon-hydrogen alloy films , 1983 .

[7]  M. Konagai,et al.  Inclusion of nanosized silicon grains in hydrogenated protocrystalline silicon multilayers and its relation to stability , 2006 .

[8]  S. M. Iftiquar,et al.  Wide optical-gap a-SiO:H films prepared by rf glow discharge , 1997 .

[9]  Yue Wang,et al.  Structural and optical properties of a-Si:H/nc-Si:H thin films grown from Ar–H2–SiH4 mixture by plasma-enhanced chemical vapor deposition , 2003 .

[10]  Hitoe Habuchi,et al.  Hydrogen structures and the optoelectronic properties in transition films from amorphous to microcrystalline silicon prepared by hot-wire chemical vapor deposition , 2003 .

[11]  Ihsanul Afdi Yunaz,et al.  Theoretical Analysis of Amorphous Silicon Alloy Based Triple Junction Solar Cells , 2007 .

[12]  Makoto Konagai,et al.  Silicon-based thin-film solar cells fabricated near the phase boundary by VHF PECVD technique , 2008 .

[13]  M. Konagai,et al.  Use of a carbon‐alloyed graded‐band‐gap layer at the p/i interface to improve the photocharacteristics of amorphous silicon alloyed p‐i‐n solar cells prepared by photochemical vapor deposition , 1987 .

[14]  S. M. Iftiquar.  The roles of deposition pressure and rf power in opto-electronic properties of a-SiO:H films , 1998 .

[15]  H. Okamoto,et al.  A study of built-in potential ina-Si solar cells by means of back-surface reflected electroabsorption , 1983 .