In order to figure out the origin of the improvement of the photo-electrochemical performance of the re-growth treated hematite, in which the deposition process was repeatedly performed, resulting in the reduction of the amount of the defect states, we investigated the photo-excited charge carrier dynamics in both bare and re-growth treated hematite films under the bias condition using heterodyne transient grating technique. In this study, we were able to observe the strong dependence of the signal intensities of the components appearing in the responses of the re-growth treated hematite film on the applied bias voltage, which was attributed to the Fermi level unpinning, caused by the reduction of the surface defect states.

为了弄清楚重新生长处理的赤铁矿的光电化学性能改善的根源，其中重复进行沉积过程，从而减少了缺陷态的数量，我们研究了光化学-外差瞬变光栅技术在偏压条件下裸露和重新生长处理的赤铁矿薄膜中的激发电荷载流子动力学。在这项研究中，我们能够观察到在重新生长处理的赤铁矿膜的响应中出现的组分信号强度对施加的偏置电压的强烈依赖性，这归因于还原引起的费米能级未钉扎表面缺陷状态。