Tantalum nitride (Ta₃N₅) is a visible-light-responsive semiconductor that may be capable of achieving the 10% solar-to-hydrogen (STH) efficiency required to allow the commercialization of water splitting systems. However, despite immense research efforts, the highest STH efficiency yet reported for photoanodes based on Ta₃N₅-nanorods (NRs) is only 2.7%. Therefore, it is imperative to build a theoretical foundation that explains the various loss mechanisms and their correlations with structural and material properties, so as to optimize the performance of this material. The present work devised a detailed numerical model based on an in-depth analysis of the performance characteristics of photoanodes made from either Ba-doped or undoped Ta₃N₅-NRs. This experimentally calibrated optoelectrical modelling enabled predictions of various factors related to performance loss, including optical effects, charge carrier recombination and resistive loss. Certain physical parameters, such as charge carrier lifetime, diffusion length, hole extraction rate from the NR surfaces to the electrolyte and the series resistance of the photoanode, could also be calculated. The results show that the enhanced performance obtained with Ba doping can be primarily attributed to increases in the carrier lifetime and diffusion length. The present model was recalibrated using experimental data from the literature to examine hidden effects of the NRs’ dimensions on optical and recombination losses. On this basis, various design principles are presented herein that should allow the fabrication of efficient Ta₃N₅-NRs photoanodes for commercial STH production.

中文翻译：

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探索纳米结构 Ta3N5 光阳极的基本损失：有效水氧化的设计原则

氮化钽 (Ta ₃ N ₅ ) 是一种可见光响应半导体，可能能够实现使水分解系统商业化所需的 10% 太阳能制氢 (STH) 效率。然而，尽管付出了巨大的研究努力，但基于 Ta ₃ N _{5 的光}阳极的 STH 效率最高。-纳米棒 (NRs) 仅为 2.7%。因此，必须建立一个理论基础来解释各种损耗机制及其与结构和材料特性的相关性，以优化该材料的性能。目前的工作基于对由 Ba 掺杂或未掺杂 Ta ₃ N ₅制成的光阳极性能特征的深入分析，设计了一个详细的数值模型。-NR。这种经过实验校准的光电模型能够预测与性能损失相关的各种因素，包括光学效应、电荷载流子复合和电阻损失。还可以计算某些物理参数，例如电荷载流子寿命、扩散长度、从 NR 表面到电解质的空穴提取率以及光电阳极的串联电阻。结果表明，Ba掺杂获得的增强性能主要归因于载流子寿命和扩散长度的增加。本模型使用文献中的实验数据重新校准，以检查 NR 尺寸对光学和复合损失的隐藏影响。在此基础上，本文提出了各种设计原则，应允许制造高效的 Ta用于商业 STH 生产的₃ N ₅ -NRs 光阳极。