Theory of multiphoton photoemission disclosing excited states in conduction band of individual TiO_(2) nanoparticles  

作　　者：Bochao Li Hao Li Chang Yang Boyu Ji Jingquan Lin Toshihisa Tomie 李博超;李浩;杨畅;季博宇;林景全;富江敏尚(School of Science,Changchun University of Science and Technology,Changchun 130022,China)

机构地区：[1]School of Science,Changchun University of Science and Technology,Changchun 130022,China

出　　处：《Chinese Physics B》2021年第11期69-75,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.91850109,11474040,61605017,and 61775021);the“111”Project of China(Grant No.D17017).

摘　　要：A theory of multiphoton photoemission is derived to explain the experimentally observed monotonic decrease with the wavelength in the electron yield of TiO_(2) nanoparticles(NPs)by as large as four orders of magnitude.It is found that the fitting parameter corresponds to the energy position of Ti3d e_(g) and t_(2g) states,and the derived theory is a novel diagnostic of excited states in the conduction band,very importantly,applicable to individual NPs.The difference between four-photon slope NPs and three-photon slope NPs is attributed to the difference in defect density.The success of the theory in solving the puzzling result shows that thermal emission from high-lying levels may dominate over direct multiphoton ionization in solids when the photon number larger than four is required.

关 键 词：multiphoton photoemission NANOPARTICLES thermal emission TiO_(2) 

分 类 号：O643.36[理学—物理化学] TB383.1[理学—化学]