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Understanding a mechanism behind photosensitivity in oxide materials is important to realize future photodetector devices. We have studied electrical properties of ZnO:Cu (0-2.5 at.%) films deposited by a spray technique. Here, Ag-ZnO-Ag planar configuration was used to study the Schottky barrier. Using current-voltage (I-V) characterization, a significant increment in the photocurrent is observed in all samples, indicating a photosensitivity behavior. The Schottky barrier is clearly observed in the doped sample. The Cu concentration of 1.5 at.% show the highest Schottky barrier height (0.8 eV), which may be originated from carrier trapping under dark and carrier de-trapping under ultraviolet radiation. Thus, our result is essential to improve the functionality of ZnO for photodetector applications.

Bricks are regarded as important material in building constructions. Basically, brick is processed by mixing clay and water then burnt under high temperature for a certain duration. Previous study in Indonesia shows that mixing local clay with additional materials could improve its characteristic, especially in terms of water absorption potentiality. Lampung has home industries which run brick making business traditionally. Moreover, this year Indonesian government has been organizing regional elections which attract campaigners to produce more vinyl banners as advertising media. As the event has already passed, vinyl banners eventually become environmental issue since they are not yet well managed. The aim of this study is to investigate the possibility and effect of red bricks mixtures along with vinyl banner waste. Firedclay bricks dimensions including length, width, and height are 19 cm, 9.5 cm, and 5 cm respectively. Measurement has done by employing water absorption tests. Waste-added bricks absorb more water than the conventional one, about 11% higher. However, rice-husk-ash-added bricks perform similar to the normal bricks, it has slow rate of water absorption. Absorption rate of waste-added bricks also fast and exceed the conventional and RHA-added bricks. Modified red bricks surfaces are uneven, they show cracks and rough edges.