TY - JOUR
T1 - Crystal Orientation Controlled Photovoltaic Properties of Multilayer GaAs Nanowire Arrays
AU - Han, Ning
AU - Yang, Zai Xing
AU - Wang, Fengyun
AU - Yip, Senpo
AU - Li, Dapan
AU - Hung, Tak Fu
AU - Chen, Yunfa
AU - Ho, Johnny C.
N1 - Funding Information:
This research was financially supported by the General Research Fund of the Research Grants Council of Hong Kong SAR, China (CityU 11213115), the National Natural Science Foundation of China (Grants 61504151 and 51402160), the State Key Laboratory of Multiphase Complex Systems (MPCS-2014-C-01), the Applied Basic Research Foundation of Qingdao City (Grant 14-2-4-45-jch), the Science Technology and Innovation Committee of Shenzhen Municipality (Grant JCYJ20140419115507588), and a grant from the Shenzhen Research Institute, City University of Hong Kong.
PY - 2016/6/28
Y1 - 2016/6/28
N2 - In recent years, despite significant progress in the synthesis, characterization, and integration of various nanowire (NW) material systems, crystal orientation controlled NW growth as well as real-time assessment of their growth-structure-property relationships still presents one of the major challenges in deploying NWs for practical large-scale applications. In this study, we propose, design, and develop a multilayer NW printing scheme for the determination of crystal orientation controlled photovoltaic properties of parallel GaAs NW arrays. By tuning the catalyst thickness and nucleation and growth temperatures in the two-step chemical vapor deposition, crystalline GaAs NWs with uniform, pure «110» and «111» orientations and other mixture ratios can be successfully prepared. Employing lift-off resists, three-layer NW parallel arrays can be easily attained for X-ray diffraction in order to evaluate their growth orientation along with the fabrication of NW parallel array based Schottky photovoltaic devices for the subsequent performance assessment. Notably, the open-circuit voltage of purely «111»-oriented NW arrayed cells is far higher than that of «110»-oriented NW arrayed counterparts, which can be interpreted by the different surface Fermi level pinning that exists on various NW crystal surface planes due to the different As dangling bond densities. All this indicates the profound effect of NW crystal orientation on physical and chemical properties of GaAs NWs, suggesting the careful NW design considerations for achieving optimal photovoltaic performances. The approach presented here could also serve as a versatile and powerful platform for in situ characterization of other NW materials.
AB - In recent years, despite significant progress in the synthesis, characterization, and integration of various nanowire (NW) material systems, crystal orientation controlled NW growth as well as real-time assessment of their growth-structure-property relationships still presents one of the major challenges in deploying NWs for practical large-scale applications. In this study, we propose, design, and develop a multilayer NW printing scheme for the determination of crystal orientation controlled photovoltaic properties of parallel GaAs NW arrays. By tuning the catalyst thickness and nucleation and growth temperatures in the two-step chemical vapor deposition, crystalline GaAs NWs with uniform, pure «110» and «111» orientations and other mixture ratios can be successfully prepared. Employing lift-off resists, three-layer NW parallel arrays can be easily attained for X-ray diffraction in order to evaluate their growth orientation along with the fabrication of NW parallel array based Schottky photovoltaic devices for the subsequent performance assessment. Notably, the open-circuit voltage of purely «111»-oriented NW arrayed cells is far higher than that of «110»-oriented NW arrayed counterparts, which can be interpreted by the different surface Fermi level pinning that exists on various NW crystal surface planes due to the different As dangling bond densities. All this indicates the profound effect of NW crystal orientation on physical and chemical properties of GaAs NWs, suggesting the careful NW design considerations for achieving optimal photovoltaic performances. The approach presented here could also serve as a versatile and powerful platform for in situ characterization of other NW materials.
UR - http://www.scopus.com/inward/record.url?scp=84976563862&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84976563862&partnerID=8YFLogxK
U2 - 10.1021/acsnano.6b02473
DO - 10.1021/acsnano.6b02473
M3 - Article
AN - SCOPUS:84976563862
VL - 10
SP - 6283
EP - 6290
JO - ACS Nano
JF - ACS Nano
SN - 1936-0851
IS - 6
ER -