2D materials such as graphene, hexagonal boron nitride (h‐BN), VS2, Bi2S3, and GaSe have been widely studied, because of their great potential in the field of catalysis, microelectronics, ion storage, and optoelectronics.1, 2, 3, 4, 5, 6, 7, 8, 9, 10 As one of the most significant members of 2D materials family, transition metal dichalcogenides (TMDs), such as MoS2, MoSe2, WS2, and WSe2, have attracted tremendous attention currently due to their outstanding electronic, optical, and mechanical properties.11, 12, 13, 14, 15, 16, 17, 18, 19 Monolayer MoSe2 is a sandwich structure consisting of one Mo atom and two Se atoms, and the different layers are interacted by van der Waals force.20, 21 Like MoS2, the properties of MoSe2 are also related with layer numbers; monolayer MoSe2 exhibits a direct bandgap of 1.6 eV, whereas it changes into indirect bandgap of 1.1 eV for bulk or multilayer MoSe2.22, 23 N‐type channel behavior with an average mobility of ≈50 cm2 V−1 s−1 has been investigated for field‐effect transistors (FETs) based on monolayer MoSe2,24 while for bulk MoSe2 the carrier mobility is ≈100 cm2 V−1 s−1.25 In comparison with MoS2, MoSe2 shows a stronger light absorption in the solar spectrum range.26 It has been proved that MoSe2 can absorb nearly 5%–10% of incident sunlight in a thickness less than 1 nm.26 Moreover, bandgap engineering on MoSe2 could be accomplished by forming ternary alloy of MoS2(1–x)Se2x.17, 27, 28 Owing to these appealing properties, many efforts have been devoted to exploit the applications of MoSe2 in diverse fields, including ion batteries, FETs, and photovoltaics, etc.29, 30, 31, 32, 33