High-performance radiation stable ZnO/Ag/ZnO multilayer transparent conductive electrode

The present study reports the fabrication and performance of swift heavy ion (SHI) irradiated transparent conducting electrode (TCE) having oxide-metal-oxide multilayer structure; ZnO/Ag/ZnO (ZAZ) deposited at room temperature and exhibiting electrical and optical properties comparable to that of commercial ITO. Pristine and SHI irradiated films show a good stability of electrical parameters; sheet resistance, carrier concentration and mobility of charge carriers under temperature variation from 80 to 340 K. This shows that these films are stable and hence suitable for application in this temperature range. The sputter deposited ZAZ multilayer structure has sheet resistance 24 Omega/square and average transparency 80% in the visible spectrum. The obtained values of sheet resistance and average transmittance after SHI irradiation of 100 MeV Ag ions with fluence 5E12 ions/cm(2) are 27 Omega/square and similar to 70%. Ion-induced sputtering of metal ions which get embedded in oxide layer creates centres for the scattering of light that leads to loss of -10% transparency. The crystalline ZAZ structure shows smooth surface morphology and chemical stability before and after heavy ions treatment. The change in sheet resistance of the multilayer structure in the temperature range 80-340 K (delta R-s is similar to 3.1 Omega/square for pristine and 3.14 Omega/square for SHI irradiated sample at a fluence of 5E12 ions/cm2. X-ray photoelectron spectroscopy (XPS) studies of both pristine and irradiated samples reveal that the middle layer is in metallic form and maintains its continuity even after ion irradiation.