室溫下快速合成銻化銦奈米線之電子傳輸及光響應特性

本論文成功的在室溫下經由電化學法合成單晶的銻化銦奈米線。銻化銦奈米線的合成主要與氯化鉀的濃度、沈積電位、銦銻離子的比例及時間有密切的關係。利用單根銻化銦奈米線製作的場效電晶體顯示出合成的奈米線為N型的半導體，同時具有3.6 × 1017 cm-3的電子濃度及 214.12 cm2 V-1 s-1的電子遷移率。此外，經由變溫的場效電晶體量測發現，電子遷移率會隨著溫度的增加而增加。這暗示著不純物離子的散射為降低電子遷移率的主要原因。其次，傅立葉紅外光光譜顯示銻化銦奈米線的能階伴隨著電子累積層的發生，有往短波長移的現象。電流對電壓的曲線基於金屬-半導體-金屬的模型發現，合成的銻化銦奈米線具有2.0 × 1017 cm−3的電子濃度及 446.42 cm2 V-1 s-1的電子遷移率。此外，高的電子濃度及表面累積層導致向下彎曲的能帶效果，進而降低了電子的穿隧能障。因此，銻化銦奈米線展現了一個極低的起始電場約1.84 V m−1 與門檻電場約3.36 V m−1. 最後，將銻化銦奈米線製作成金屬-半導體-金屬結構的中紅外光感測器。由於銻化銦奈米線具有高的比表面積、單晶的一維結構及高的電子遷移率，可以有效的降低電子在電極間的散射及傳遞時間。因此，中紅外光感測器可展現出優秀的光電導性、穩定性、再現性、高的反應性(8.4 × 104 A W−1)及量子效率(1.96 × 106)。另外，金屬-半導體-金屬的結構可以藉由形成肖特基接觸提高空間電荷效應，有效的幫助電子注入和增強光電流。

關鍵字

銻化銦；奈米線；電化學；電子傳輸；光反應；金屬-半導體-金屬結構

並列摘要

Vertically aligned single-crystal InSb nanowires were synthesized via the electrochemical method at room temperature. The stoichiometry of the deposited InSb nanowire is dependent on the value of KCl concentration, deposition potential, ratios of In3+/Sb3+ and and deposition time. Characteristic field-effect transistor based on InSb nanowires have N-type conductivity. Meanwhile, InSb nanowires have a electron concentration of 3.6 × 1017 cm-3 and a electron mobility of 214.12 cm2 V-1 s-1. Moreover, the mobility was observed to increase as the temperature increases, providing evidence of the ionized impurity scattering as the dominant reason of decreased mobility. In addition, the characteristics of Fourier transform infrared spectrum revealed that in the syntheses of InSb nanowires, energy bandgap shifts towards the short wavelength with the occurrence of an electron accumulation layer. The current-voltage curve, based on the metal-semiconductor-metal model, showed a high electron carrier concentration of 2.0 × 1017 cm−3 and a high electron mobility of 446.42 cm2 V−1 s−1. Additionally, the high carrier concentration of the InSb semiconductor with the surface accumulation layer induced a downward band bending effect that reduces the electron tunneling barrier. Consequently, the InSb nanowires exhibit significant field emission properties with a low turn-on field of 1.84 V m−1 and an estimate threshold field of 3.36 V m−1. Finally, single-crystal InSb nanowire was fabricated into middle-infrared (M-IR) photodetectors based on a metal-semiconductor-metal (M-S-M) structure. The photodetectors exhibit high photoconductive performance, excellent stability, reproducibility, high responsivity (8.4 × 104 A W-1), and quantum efficiency (1.96 × 106). These superior properties are attributed to the single-crystal 1D nanostructure and high electron mobility of photodetectors that significantly reduce the scattering and the transit time between the electrodes during the transport process. Furthermore, the M-S-M structure can effectively enhance space charge effect by the formation of the Schottky contacts, which significantly assists with the electron injection and photocurrent gain.

並列關鍵字

InSb ； Nanowires ； Electrochemical method ； Electrical transport ； Photoresponsive ； Metal-semiconductor-metal structure

參考文獻

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室溫下快速合成銻化銦奈米線之電子傳輸及光響應特性

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