Monoclinic　gallium　oxide　(bGa2O3　)　is　an　emerging　wide　bandgap　semiconductor　with　an　ultrawide　bandgap　(~　4.　9　eV)　at　room　temperature,　an　high　breakdown　field　strength　(~8　MV/　cm),　a　Baligas　figure　of　merit　(BFOM)　of　3　400,　and　availability　of　native　single　crystal　substrates　using　inexpensive　meltbased　growth　methods.　These　attractive　properties　of　bGa2　O3　make　it　an　ideal　candidate　for　potential　applications　such　as　highpower　electronic　devices　and　solar　blind　ultraviolet　(UV)　photodetectors.　It　is　well　known　that　the　high　quality　epitaxial　layer　is　the　prerequisite　for　the　fabrication　of　high　performance　devices.　Up　to　now,　the　bGa2　O3　epitaxial　layers　have　been　prepared　by　various　methods,　and　several　kinds　of　devices　have　been　fabricated.　However,　many　challenges　still　exist,　including　heteroepitaxial　growth　maturity,　ptype　doping,　and　device　performance　optimization.　This　article　reviews　the　current　status　of　the　synthesis　technologies,　the　substrates　for　homoepitaxy　/　heteroepitaxy,　doping,　electrical　properties　and　the　applications　of　power　devices　and　ultraviolet　photodetectors.　©　2022　Cailiao　Daobaoshe/　Materials　Review.　All　rights　reserved.