Point and complex defects in monolayer PdSe2: Evolution of electronic structure and emergence of magnetism

Описание

Тип публикации: статья из журнала

Год издания: 2021

Идентификатор DOI: 10.1103/PhysRevB.104.134109

Аннотация: Layered transition-metal dichalcogenides (TMDs) constitute an emerging class of materials that provide researchers a platform to realize fundamental studies and to design promising optoelectronic devices. While defects are an almost unavoidable part of TMDs, they bring additional interesting properties absent in defect-free layers.Показать полностьюMoreover, the controlled introduction of defects in TMDs makes it possible to tailor the electromagnetic properties of the materials. Here we report defect-induced properties of single-layer PdSe2 and demonstrate the emergence of magnetism at the nanoscale. Our first-principle calculations indicate that Se vacancies create in-gap defect states, which can be responsible for trapping of carriers. The complex square VPd+4Se vacancy induces spin-polarized states with a total local magnetic moment of 2μB per defect, making it possible to introduce magnetization into PdSe2 and therefore expand the family of two-dimensional (2D) magnets. The defect formation energies are much lower compared to many other TMD materials that can explain the presence of a large number of Se defects after mechanical exfoliation of PdSe2 layers, while the central location of the Pd atoms preserves them from exfoliation-induced defect formation. The negatively charged vacancies are prone to form and in many cases demonstrate spin-polarized states. The small diffusion barrier of VSe in 2D PdSe2 leads to an easy room-temperature migration, while VPd demonstrates a high diffusion barrier preventing its spontaneous migration. As a guide for experimentalists, we simulate and characterize scanning tunneling microscope images in valence and conduction states and estimate the electron-beam energy for a controllable production of various defect patterns. These intriguing findings make PdSe2 an ideal platform to study defect-induced phenomena. © 2021 authors. Published by the American Physical Society.

Ссылки на полный текст

Издание

Журнал: Physical Review B

Выпуск журнала: Vol. 104, Is. 13

Номера страниц: 134109

ISSN журнала: 24699950

Издатель: American Physical Society

Персоны

  • Kuklin Artem (Siberian Fed Univ, Int Res Ctr Spect & Quantum Chem IRC SQC, 79 Svobodny Pr, Krasnoyarsk 660041, Russia; Uppsala Univ, Dept Phys & Astron, SE-75120 Uppsala, Sweden)
  • Begunovich Lyudmila (Siberian Fed Univ, Int Res Ctr Spect & Quantum Chem IRC SQC, 79 Svobodny Pr, Krasnoyarsk 660041, Russia)
  • Gao Lingfeng (Hangzhou Normal Univ, Coll Mat Chem & Chem Engn, 2318 Yuhangtang Rd, Hangzhou 311121, Peoples R China)
  • Zhang Han (Shenzhen Univ, Inst Microscale Optoelect,Collaborat Innovat Ctr, Minist Educ & Guangdong Prov,Guangdong Lab Artifi, Coll Phys & Optoelect Engn,Shenzhen Key Lab Micro, Shenzhen 518060, Peoples R China)
  • Agren Hans (Siberian Fed Univ, Int Res Ctr Spect & Quantum Chem IRC SQC, 79 Svobodny Pr, Krasnoyarsk 660041, Russia; Uppsala Univ, Dept Phys & Astron, SE-75120 Uppsala, Sweden; Henan Univ, Coll Chem & Chem Engn, Kaifeng 475004, Henan, Peoples R China; Tomsk State Univ, 36 Lenin Ave, Tomsk, Russia)

Вхождение в базы данных