nanomaterials Review Recent Advances in Electrical Doping of 2D Semiconductor Materials: Methods, Analyses, and Applications Hocheon Yoo 1,2,† , Keun Heo 3,† , Md. Hasan Raza Ansari 1,2 and Seongjae Cho 1,2,* 1 Department of Electronic Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea;
[email protected] (H.Y.);
[email protected] (M.H.R.A.) 2 Graduate School of IT Convergence Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea 3 Department of Semiconductor Science & Technology, Jeonbuk National University, Jeonju-si, Jeollabuk-do 54896, Korea;
[email protected] * Correspondence:
[email protected] † These authors contributed equally to this work. Abstract: Two-dimensional materials have garnered interest from the perspectives of physics, materi- als, and applied electronics owing to their outstanding physical and chemical properties. Advances in exfoliation and synthesis technologies have enabled preparation and electrical characterization of various atomically thin films of semiconductor transition metal dichalcogenides (TMDs). Their two-dimensional structures and electromagnetic spectra coupled to bandgaps in the visible region indicate their suitability for digital electronics and optoelectronics. To further expand the potential applications of these two-dimensional semiconductor materials, technologies capable of precisely controlling the electrical properties of the material are essential. Doping has been traditionally used to effectively change the electrical and electronic properties of materials through relatively simple processes. To change the electrical properties, substances that can donate or remove electrons are Citation: Yoo, H.; Heo, K.; added. Doping of atomically thin two-dimensional semiconductor materials is similar to that used Ansari, M..H.R.; Cho, S.