Reddy B Kumaar Swamy, Veeralingam Sushmitha, Borse Pramod H, Badhulika Sushmee
Department of Electrical Engineering, Indian Institute of Technology-Hyderabad, Kandi, Sangareddy, Hyderabad, India.
Centre for Nanomaterials, International Advanced Research Centre for Powder, Metallurgy & New Materials, Balapur, Hyderabad, India.
Nanotechnology. 2022 Mar 15;33(23). doi: 10.1088/1361-6528/ac5838.
Conventional heterojunction photodetectors rely on planar junction architecture which suffer from low interfacial contact area, inferior light absorption characteristics and complex fabrication schemes. Heterojunctions based on mixed dimensional nanostructures such as 0D-1D, 1D-2D, 1D-3D etc have recently garnered exceptional research interest owing to their atomically sharp interfaces, tunable junction properties such as enhanced light absorption cross-section. In this work, a flexible broadband UV-vis photodetector employing mixed dimensional heterostructure of 1D NiO nanofibers and 3D FeOnanoparticles is fabricated. NiO nanofibers were synthesized via economical and scalable electro-spinning technique and made composite with FeOnanoclusters for hetero-structure fabrication. The optical absorption spectra of NiO nanofibers and FeOnanoparticles exhibit peak absorption in UV and visible spectra, respectively. The as-fabricated photodetector displays quick response times of 0.09 s and 0.18 s and responsivities of 5.7 mA W(0.03 mW cm) and 5.2 mA W(0.01 mW cm) for UV and visible spectra, respectively. The fabricated NiO-FeOdevice also exhibits excellent detectivity in the order of 10jones. The superior performance of the device is ascribed to the type-II heterojunction between NiO-FeOnanostructures, which results in the localized built-in potential at their interface, that aids in the effective carrier separation and transportation. Further, the flexible photodetector displays excellent robustness when bent over ∼1000 cycles thereby proving its potential towards developing reliable, diverse functional opto-electronic devices.
传统的异质结光电探测器依赖于平面结结构，这种结构存在界面接触面积小、光吸收特性差以及制造方案复杂等问题。基于混合维度纳米结构（如0D-1D、1D-2D、1D-3D等）的异质结，由于其原子级锐利的界面、可调谐的结特性（如增强的光吸收截面），最近引起了特别的研究兴趣。在这项工作中，制备了一种采用1D NiO纳米纤维和3D FeO纳米颗粒混合维度异质结构的柔性宽带紫外-可见光电探测器。通过经济且可扩展的静电纺丝技术合成了NiO纳米纤维，并与FeO纳米团簇复合以制备异质结构。NiO纳米纤维和FeO纳米颗粒的光吸收光谱分别在紫外和可见光谱中表现出峰值吸收。所制备的光电探测器在紫外和可见光谱下的响应时间分别为0.09 s和0.18 s，响应度分别为5.7 mA W⁻¹(0.03 mW cm⁻²)和5.2 mA W⁻¹(0.01 mW cm⁻²)。所制备的NiO-FeO器件还表现出约10¹²琼斯的优异探测率。该器件的优异性能归因于NiO-FeO纳米结构之间的II型异质结，这导致其界面处的局部内建电势，有助于有效的载流子分离和传输。此外，该柔性光电探测器在弯曲约1,000次循环时仍表现出出色的稳健性，从而证明了其在开发可靠、多功能光电器件方面的潜力。
