Liu Shu-Yen, Sheu J K, Lin Yu-Chuan, Tu S J, Huang F W, Lee M L, Lai W C
Department of Photonics & Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan City 70101, Taiwan.
Opt Express. 2012 Sep 10;20 Suppl 5:A678-83. doi: 10.1364/OE.20.00A678.
Hydrogen generation through direct photoelectrolysis of water was studied using photoelectrochemical (PEC) cells made of Mn-doped GaN photoelectrodes. In addition to its absorption of the ultraviolet spectrum, Mn-doped GaN photoelectrodes could absorb photons in the visible spectrum. The photocurrents measured from PEC cells made of Mn-doped GaN were at least one order higher than those measured from PEC cells made of undoped GaN-working electrodes. Under the visible light illumination and a bias voltage below 1.2 V, the Mn-doped GaN photoelectrodes could drive the water splitting reaction for hydrogen generation. However, hydrogen generation could not be achieved under the same condition wherein undoped GaN photoelectrodes were used. According to the results of the spectral responses and transmission spectra obtained from the experimental photoelectrodes, the enhanced photocurrent in the Mn-doped GaN photoelectrodes, compared with the undoped GaN photoelectrodes, was attributable to the Mn-related intermediate band within the band gap of GaN that resulted in further photon absorption.
利用由锰掺杂氮化镓光电极制成的光电化学（PEC）电池，研究了通过水的直接光电解产生氢气的过程。除了吸收紫外光谱外，锰掺杂氮化镓光电极还能吸收可见光谱中的光子。由锰掺杂氮化镓制成的PEC电池测得的光电流比由未掺杂氮化镓工作电极制成的PEC电池测得的光电流至少高一个数量级。在可见光照射和低于1.2V的偏置电压下，锰掺杂氮化镓光电极可以驱动水分解反应以产生氢气。然而，在使用未掺杂氮化镓光电极的相同条件下无法实现氢气的产生。根据从实验光电极获得的光谱响应和透射光谱结果，与未掺杂氮化镓光电极相比，锰掺杂氮化镓光电极中光电流的增强归因于氮化镓带隙内与锰相关的中间带，这导致了进一步的光子吸收。
