Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator device includes a substrate, a single-crystal lithium niobate plate, an acoustic Bragg reflector sandwiched between a surface of the substrate and a back surface of the lithium niobate plate, wherein the acoustic Bragg reflector includes a plurality of layers alternating between high acoustic impedance layers and low acoustic impedance layers, wherein all of the plurality of layers are dielectric materials, and wherein the high acoustic impedance layers are one of silicon nitride and aluminum nitride and the low acoustic impedance layers are carbon-containing silicon oxide, and an interdigital transducer (IDT) formed on a front surface of the lithium niobate plate. Euler angles of the lithium niobate plate are [0°, β, 0°], where β is greater than or equal to 0° and less than or equal to 60°.