Optical, structural and photo-electric properties of Zn 1−x−y Mg x Al y O films on piezoelectric LiNbO 3 substrates prepared by PLD method at varied temperatures are studied. The ZnO band gap is enlarged to ∼5 eV by Mg atoms dosing. The reduced growth temperature of 400 °C results in lower conductivity of the film. The films grown at 400 °C-500 °C show deep UV photoelectrical response of 0.1-0.2 ms which is 50-100 times faster compared to devices based on films produced at 600 °C with higher crystallinity. By moderate Al doping and varying the temperature of Zn(Mg, Al)O film growth one may tune the initial sheet conductivity, i.e. the 'working point' of UV SAW detector, to the abrupt slopes of Γ(σ) characteristics, thus, optimizing the sensor sensitivity and response time. The UV 'light on/off' sheet conductivity change Δσ/σ dark , defining the sensitivity of UV SAW photodetector is tuned between ∼22% and ∼0.4%.

No abstract

No abstract

No abstract

A tunable high-Q surface acoustic wave (SAW) resonator in the form of several parallel-connected interdigital transducers loaded on a varying capacitance on lithium niobate substrates was developed and studied. The working frequency range was 90–2450[Formula: see text]MHz. A method of calculating such resonators, considering losses in the metal film as well as losses due to the propagation of SAWs and transformations into bulk waves is proposed. Such a design allows one to obtain a quality factor over 5000 in the frequency range 2400–2483[Formula: see text]MHz. The resonant frequency shifts by 600[Formula: see text]kHz when the capacitance changes by [Formula: see text]% of the value of 21[Formula: see text]pF (or 32[Formula: see text]ppm/pF) and has an almost linear character.