Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China.
Nanoscale. 2018 Jul 13;10(27):13028-13036. doi: 10.1039/c8nr02824a.
Utilizing high-energy beta particles emitted from radioisotopes for long-lifetime betavoltaic cells is a great challenge due to their low energy conversion efficiency (ECE). Here we report a betavoltaic cell fabricated using black titania nanotube arrays (TiO2 NTAs) by electrochemical anodization and Ar-annealing techniques. The obtained samples show enhanced electrical conductivity as well as Vis-NIR light absorption by the introduction of oxygen vacancy (OV) and Ti3+ defects in reduced TiO2-x NTAs. A 20 mCi63 Ni source was assembled into TiO2 NTAs to form a sandwich-type betavoltaic cell. By I-V measurements, the Ar-annealed TiO2 NTAs at 650 °C exhibited a maximum ECE of 3.65% with Voc = 1.13 V, Jsc = 103.3 nA cm-2, and Pmax = 37 nW cm-2. In comparison with air-annealed TiO2 NTAs, the enhancement of the betavoltaic effect in reduced TiO2-x NTAs can be attributed to the suppression of e-h recombination induced by the generation of OV and Ti3+ defects, serving as electron donors as well as electron traps that not only contribute to the increase of electrical conductance, but also facilitate the charge carrier separation.
利用放射性同位素发射的高能 β 粒子为长寿命β伏电池供电是一项巨大的挑战，因为它们的能量转换效率 (ECE) 很低。在这里，我们报告了一种使用电化学阳极氧化和 Ar 退火技术制备的使用黑二氧化钛纳米管阵列 (TiO2 NTAs) 的 β 伏电池。通过引入氧空位 (OV) 和 Ti3+ 缺陷，获得的样品表现出增强的导电性以及对 Vis-NIR 光的吸收，减少的 TiO2-x NTAs。将 20 mCi63 Ni 源组装到 TiO2 NTAs 中，形成三明治型 β 伏电池。通过 I-V 测量，在 650°C 下退火的 Ar TiO2 NTAs 表现出最大 ECE 为 3.65%，Voc = 1.13 V，Jsc = 103.3 nA cm-2 和 Pmax = 37 nW cm-2。与空气退火的 TiO2 NTAs 相比，减少的 TiO2-x NTAs 中 β 伏效应的增强归因于 OV 和 Ti3+ 缺陷产生引起的 eh 复合的抑制，它们既是电子供体又是电子陷阱，不仅有助于增加电导率，而且还促进了载流子分离。
