Electrical properties
ZnO has a relatively large direct band gap of ~3.3 eV at room temperature. Advantages associated with a large band gap include higher breakdown voltages, ability to sustain large electric fields, lower electronic noise, and high-temperature and high-power operation. The band gap of ZnO can further be tuned to ~3–4 eV by its alloying with magnesium oxide or cadmium oxide.[12]
Most ZnO has n-type character, even in the absence of intentional doping. Nonstoichiometry is typically the origin of n-type character, but the subject remains controversial.[30] An alternative explanation has been proposed, based on theoretical calculations, that unintentional substitutional hydrogen impurities are responsible.[31] Controllable n-type doping is easily achieved by substituting Zn with group-III elements such as Al, Ga, In or by substituting oxygen with group-VII elements chlorine or iodine.[32]
Reliable p-type doping of ZnO remains difficult. This problem originates from low solubility of p-type dopants and their compensation by abundant n-type impurities. This problem is observed with GaN and ZnSe. Measurement of p-type in "intrinsically" n-type material is complicated by the inhomogeneity of samples.[33]
Current limitations to p-doping limit electronic and optoelectronic applications of ZnO, which usually require junctions of n-type and p-type material. Known p-type dopants include group-I elements Li, Na, K; group-V elements N, P and As; as well as copper and silver. However, many of these form deep acceptors and do not produce significant p-type conduction at room temperature.[12]
Electron mobility of ZnO strongly varies with temperature and has a maximum of ~2000 cm2/(V·s) at 80 K.[34] Data on hole mobility are scarce with values in the range 5–30 cm2/(V·s).[35]
ZnO discs, acting as a varistor, are the active material in most surge arresters.[36][37]
the elevated band gap means it needs a higher electric field to become conductor... its used as a varistor element because when it reach a certain voltage field it become conductive and its resistance is restored when the field applied is not there anymore.
it may have a function in the cell working as a sort of dielectric? thats what you mean?
did you verify what is the lowest voltage at witch you will have current flow?
i was testing with potassium nitrate and ss and it need twice the voltage required than potassium hydroxide for example..
i think is possible to plate zinc over an electrode of copper or iron.. pehaps with some zinc sulfate and a piece of metalic zinc...
https://media.pearsoncmg.com/bc/bc_0media_chem/chem_sim/html5/Electro/Electro.php
