Research On Electrical Properties Of Gallium Arsenide Nanowire PN Junction

The research work is mainly supported by the grants from National Basic Research Program of China (No.2010CB327600)-Basic Research on Compatible Heterogeneous Integration and Functional-Microstructure Assemblage for the Development of Novel Optoelectronic Devices, the National Natural Science Foundation of China (6102010600and61077049), New Century Excellent Talents in University (NCET-08-0736), the111Program of China (B07005) and BUPT Excellent Ph.D. Students Foundation (CX201213).Semiconductor nanowire-based pn junction provides one of most ideal functionalities for building nanoscale devices. The electrical property of nanowire-based pn junction is one of the most important parameter that has to be considered while building nanowire scale devices. However, systemetical studies on electrical properties of nanowire-based pn junction are still lacking. In this paper, theoretical and experimental work is lanched about electrical properties of gallium arsenide nanowire pn junctions. The main achivements are listed as follows:1、All possible elements which may make inflence the electrical properties of nanowire-based pn junctions are investigated theoretically using a software. Main conlusions are:(1) The average growth density, diamter, doping concentration and length of nanowire has almost no influence on the dark current and turn-on voltage of GaAs nanowire-based substrate-nanowire pn jucntion array.(2) Total current through p-n junction is approximately linear proportional to NW growth density after the junction is conducted. Increasing NW doping concentration and diameter or decreasing NW length can enlarge the total current through the junctions.(3) The substrate-nanowires p-n junctions have larger current than that of substrate-layer p-n junction, which implies the superiority of nanowire structure.2、In experiments, we fabricate GaAs substrate-nanowire pn junction array using MOCVD. The experiment implies that the average growth density of nanowires can be controlled by the amount of Au solution as catalyst. The length of growth time has influence on nanowires’length. After some processing, the electrode is fabricated, and the electrical property of GaAs substrate-nanowire pn junction array is measured, the result shows that the fabricated GaAs substrate-nanowire pn junction array exhibits clear diode characteristics and its turn-on voltage is about0.7Volt.