Electric field influenced ZnO growth on nanoscale etched Si surface by continuous spray pyrolysis

This work reports ZnO growth by electric field influenced continuous spray pyrolysis reactor over seed layer assisted nanoscale etched Si surface. The comparative studies of ZnO growth in the presence and absence electric field on anisotropically etched Si surface are supported by XRD, SEM, EDX, FTIR and reflectance measurements. XRD measurements confirm preferable (002) oriented ZnO growth by certain amount of etching which is reduced with further anisotropic etching. The chlorine incorporation in ZnO thin film measured by EDX and FTIR may be attributed to the seed layer effect. This present investigation show that anisotropic etch pits surface energy profile has played an important role in deciding ZnO nanorods alignment and coalescence amongst ZnO species during self assembly at nucleation sites. It is observed that additional electric field force in spray droplets is enhancing population density, homogeneous growth and surface coverage of Si surface by ZnO nanorods for particular amount of etched Si surface and improved light coupling is confirmed by reflectance measurement. The relevant growth mechanisms for ZnO nanostructure layers comprising nanorods are also discussed.