Solar water splitting is a promising approach to develop the renewable energy. [1] Due to the excellent solution stability, earth abundance and suitable band gap, hematite is one of the most promising photoanode with n-type characteristics. [2] Nevertheless the high carrier recombination, [3] slow reaction kinetics [4] and mismatch of the band edge with the water splitting potentials [5] suppress the further promotion of its photolelectrochemical (PEC) performance. Combining with p-type material is an efficient way to tune the band structure and improve the charge carrier separation of hematite. Mg doped-hematite film with p-type characteristics was fabricated by atomic layer deposition (ALD) and significantly reduced the onset potential for photocurrent. [6] Recently, the perovskite LaFeO₃ with band gap of 2.07eV are fabricated with intrinsic p-type characteristics and exhibit a high hydrogen evolution rate under visible light. [7, 8] Here we report the fabrication of p-type La: Fe₂O₃ and the n-p junction of Fe₂O₃/La: Fe₂O₃ by ALD technique for its excellent conformability and controllable film growth with low defect densities. We will demonstrate the La: Fe₂O₃ film with p-type characteristics with Mott−Schottky plots and Hall Effect. The cathodic photocurrent as well as the PEC performance will also be discussed. By preparing the n-p junction of Fe₂O₃/La: Fe₂O₃, we design to reduce the onset potential for the photocurrent more than 100 mV comparing to the pure Fe₂O₃ photoanode. The incident photon-to-current conversion efficiency (IPCE) of Fe₂O₃/La: Fe₂O₃ n-p junction can be increased more than 10% at 400 nm. The PEC performance, and its mechanism will also be discussed. References: F. E. Osterloh, Chem. Soc. Rev., 42, 2294 (2013). K. Sivula, F. L. Formal, M. Grätzel, Chem. Sus. Chem, 4, 432. (2011) M. P. Dareedwards, J. Chem. Soc. Faraday Trans. 1, 79, 2027 (1983). K. J McDonald, K. S. Choi, Chem. Mater., 23, 1686 (2011). J. Brillet, M. Cornuz, F. L. Formal, J. H Yum, M. Grätzel, K. Sivula, J. Mater. Res., 25, 17 (2010). Y. Lin, Y. Xu, M. T. Mayer, Z. I. Simpson, G. McMahon, S. Zhou , D. Wang, J. Am. Chem. Soc., 134, 5508 (2012). Q. Yu, X. G. Meng, T. Wang, P. Li, L. Q. Liu, K. Chang, G. G. Liu and J. Ye, Chem. Commun., 2015, 51, 3630. Q. Peng, J. Wang, Y. W. Wen, B. Shan, R. Chen, RSC Adv., 6, 26192 (2016).