College of Electronic Information and Optical Engineering and Tianjin Key Laboratory of Photoelectronic Thin Film Devices and Technology, Nankai University , Tianjin 300071, China.
ACS Appl Mater Interfaces. 2017 Jun 7;9(22):18682-18690. doi: 10.1021/acsami.7b01388. Epub 2017 May 26.
Electrodepositon of Ga film is very challenging due to the high standard reduction potential (-0.53 V vs SHE for Ga). In this study, Ga film with compact structure was successfully deposited on the Mo/Cu/In substrate by the pulse current electrodeposition (PCE) method using GaCl aqueous solution. A high deposition rate of Ga and H can be achieved by applying a large overpotential induced by high pulse current. In the meanwhile, the concentration polarization induced by cation depletion can be minimized by changing the pulse frequency and duty cycle. Uniform and smooth Ga film was fabricated at high deposition rate with pulse current density 125 mA/cm, pulse frequency 5 Hz, and duty cycle 0.25. Ga film was then selenized together with electrodeposited Cu and In films to make a CIGSe absorber film for solar cells. The solar cell based on the Ga film presents conversion efficiency of 11.04%, fill factor of 63.40%, and V of 505 mV, which is much better than those based on the inhomogeneous and rough Ga film prepared by the DCE method, indicating the pulse current electrodeposition process is promising for the fabrication of CIGSe solar cell.
由于 Ga 的标准还原电位（相对于 SHE 为-0.53V）较高，因此 Ga 薄膜的电沉积极具挑战性。在这项研究中，使用 GaCl 水溶液通过脉冲电流电沉积（PCE）方法成功在 Mo/Cu/In 基底上沉积了具有致密结构的 Ga 薄膜。通过施加由高脉冲电流引起的大过电位，可以实现 Ga 和 H 的高沉积速率。同时，通过改变脉冲频率和占空比，可以最小化阳离子耗尽引起的浓度极化。在脉冲电流密度为 125mA/cm、脉冲频率为 5Hz 和占空比为 0.25 的条件下，以高沉积速率制备出均匀、光滑的 Ga 薄膜。然后，将 Ga 薄膜与电沉积的 Cu 和 In 薄膜一起硒化，以制备用于太阳能电池的 CIGSe 吸收层薄膜。基于 Ga 薄膜的太阳能电池表现出 11.04%的转换效率、63.40%的填充因子和 505mV 的 V，这明显优于通过 DCE 方法制备的不均匀和粗糙 Ga 薄膜制备的太阳能电池，表明脉冲电流电沉积工艺有望用于制造 CIGSe 太阳能电池。
