Shukla Preeti, Yadav Sarita, Patel M S, Kumar Pramendra, Kumar Naresh, Kumar Lokendra
Molecular Electronics Research Laboratory, Physics Department, Faculty of Science, University of Allahabad, Prayagraj-211 002, India.
Department of Applied Chemistry, IET, M. J. P. Rohilkhand University, Bareilly-243 006, India.
Nanotechnology. 2021 May 7;32(19):195208. doi: 10.1088/1361-6528/abe070.
Highly luminescent all-inorganic cesium lead bromide (CsPbBr) perovskite quantum dots (QDs) have been extensively used as a photosensitizer in optoelectronic devices, while p-type small-organic-molecule copper phthalocyanine (CuPc) is also widely used as a photoactive material in solar cells, organic field-effect transistors (OFETs), etc. In this paper, we report the preparation of a CsPbBr-QDs/CuPc heterostructure to study the effect of CsPbBr-QDs on CuPc. The optical properties of both CuPc and the QDs/CuPc heterostructure were compared and contrasted using UV-vis absorbance and photoluminescence (PL) measurements. Furthermore, to study their electronic and charge transfer features, we fabricated field-effect transistors (FETs) on both pristine CuPc and QDs/CuPc heterostructure thin films and studied their photoresponsive electrical characteristics. Both pristine and QDs/CuPc-based FETs showed an enhancement in current and carrier mobility under illumination. The enhancement in the current and carrier mobility of the QDs/CuPc-based FETs is due to a large number of photoexcited charge carriers. We also observed that the current and carrier mobility in the QDs/CuPc heterostructure-based FET were lower than those of the pristine CuPc-based FET. This can be explained by the n-type doping effect of CsPbBr QDs on CuPc, which reduces the accumulation of holes in the active p-channel near the insulating layer and causes charge to be transferred from the QDs to the CuPc. Thus, we have observed a charge transfer effect in the CsPbBr QDs/CuPc heterostructure, which can be used in optoelectronic devices.
高发光性的全无机铯铅溴化物（CsPbBr）钙钛矿量子点（QDs）已被广泛用作光电器件中的光敏剂，而p型小分子铜酞菁（CuPc）也被广泛用作太阳能电池、有机场效应晶体管（OFET）等中的光活性材料。在本文中，我们报告了CsPbBr量子点/CuPc异质结构的制备，以研究CsPbBr量子点对CuPc的影响。使用紫外可见吸收光谱和光致发光（PL）测量对CuPc和量子点/CuPc异质结构的光学性质进行了比较和对比。此外，为了研究它们的电子和电荷转移特性，我们在原始CuPc和量子点/CuPc异质结构薄膜上制备了场效应晶体管（FET），并研究了它们的光响应电学特性。原始的和基于量子点/CuPc的FET在光照下均显示出电流和载流子迁移率的增强。基于量子点/CuPc的FET中电流和载流子迁移率的增强归因于大量的光激发电荷载流子。我们还观察到基于量子点/CuPc异质结构的FET中的电流和载流子迁移率低于原始的基于CuPc的FET。这可以通过CsPbBr量子点对CuPc的n型掺杂效应来解释，该效应减少了绝缘层附近有源p沟道中空穴的积累，并导致电荷从量子点转移到CuPc。因此，我们在CsPbBr量子点/CuPc异质结构中观察到了电荷转移效应，该效应可用于光电器件。
