ZnO　is　a　wide-bandgap　(3.37　eV　at　room　temperature)　oxide　semiconductor　that　is　attractive　for　its　great　potential　in　short-wavelength　optoelectronic　devices,　in　which　high　quality　films　and　heterostructures　are　essential　for　high　performance.　In　this　study,　controlled　growth　of　ZnO-based　thin　films　and　heterostructures　by　molecular　beam　epitaxy　(MBE)　is　demonstrated　on　different　substrates　with　emphasis　on　interface　engineering.　It　is　revealed　that　ultrathin　AlN　or　MgO　interfacial　layers　play　a　key　role　in　establishing　structural　and　chemical　compatibility　between　ZnO　and　substrates.　Furthermore,　a　quasi-homo　buffer　is　introduced　prior　to　growth　of　a　wurtzite　MgZnO　epilayer　to　suppress　the　phase　segregation　of　rock-salt　MgO,　achieving　wide-range　bandgap　tuning　from　3.3　to　4.55　eV.　Finally,　a　visible-blind　UV　detector　exploiting　a　double　heterojunction　of　n-ZnO/insuIator-MgO/p-Si　and　a　solar-blind　UV　detector　using　MgZnO　as　an　active　layer　are　fabricated　by　using　the　growth　techniques　discussed　here.