Wang Shengyong, Liu Huan, Pan Yongqiang, Xie Fei, Zhang Yan, Zhao Jijie, Wen Shuai, Gao Fei
School of Optoelectronic Engineering, Xi'an Technological University, Xi'an 710021, China.
Nanomaterials (Basel). 2022 Aug 26;12(17):2956. doi: 10.3390/nano12172956.
Silver nanowires (AgNWs) are used as transparent electrodes (TE) in many devices. However, the contact mode between the nanowires is the biggest reason why the sheet resistance of silver nanowires is limited. Here, simple and effective ultraviolet (UV) irradiation welding is chosen to solve this problem. The influence of the power density of the UV irradiation on welding of the silver nanowires is studied and the fixed irradiation time is chosen as one minute. The range of the UV (380 nm) irradiation power is chosen from 30 mW/cm to 150 mW/cm. First of all, the transmittance of the silver nanowire film is not found to be affected by the UV welding (400-11,000 nm). The sheet resistance of the silver nanowires decreases to 73.9% at 60 mW/cm and increases to 127.6% at 120 mW/cm. The investigations on the UV irradiation time reveal that the sheet resistance of the AgNWs decreases continuously when the UV irradiation time is varied from 0 to 3 min, and drops to 57.3% of the initial value at 3 min. From 3-6 min of the continuous irradiation time, the change of the sheet resistance is not obvious, which reflects the self-limiting and self-termination of AgNWs welding. By changing the wavelength of the UV irradiation from 350-400 nm, it is found that the welding effect is best when the UV wavelength is 380 nm. The average transmittance, square resistance, and the figure of merit of the welded AgNWs at 400-780 nm are 95.98%, 56.5 Ω/sq, and 117.42 × 10 Ω, respectively. The UV-welded AgNWs are also used in silicon-based photodetectors, and the quantum efficiency of the device is improved obviously.
银纳米线（AgNWs）在许多器件中被用作透明电极（TE）。然而，纳米线之间的接触模式是银纳米线薄层电阻受限的最大原因。在此，选择简单有效的紫外线（UV）辐照焊接来解决这一问题。研究了UV辐照功率密度对银纳米线焊接的影响，并选择固定辐照时间为1分钟。UV（380nm）辐照功率范围选择为30mW/cm至150mW/cm。首先，未发现UV焊接（400 - 11,000nm）会影响银纳米线薄膜的透光率。银纳米线薄层电阻在60mW/cm时降至73.9%，在120mW/cm时升至127.6%。对UV辐照时间的研究表明，当UV辐照时间从0变化到3分钟时，AgNWs的薄层电阻持续下降，在3分钟时降至初始值的57.3%。在连续辐照3 - 6分钟时，薄层电阻变化不明显，这反映了AgNWs焊接的自限性和自终止性。通过将UV辐照波长从350 - 400nm改变，发现当UV波长为380nm时焊接效果最佳。焊接后的AgNWs在400 - 780nm处的平均透光率、方阻和品质因数分别为95.98%、56.5Ω/sq和117.42×10Ω。UV焊接的AgNWs还用于硅基光电探测器，器件的量子效率得到明显提高。
