Thermal evaporation of ZnO and mixture of ZnO and SiO for developing latent fingerprints

• Main Authors: Wang-Cheng Hsieh, 謝旺成
• Other Authors: Shyankay Jou
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/jndt5f

碩士 === 國立臺灣科技大學 === 材料科學與工程系 === 99 === In this research, development of latent fingerprint can be achieved by thermal evaporation using various oxide sources and simple procedures without annealing. Results shows that latent fingerprints can be clearly developed and behave luminescence-emitting property in specific condition, which is beneficial to forensic science. Latent fingerprint can be successfully developed using ZnO, Zn(OH)2, and Zn(NO3)2, respectively. Films exhibit metallic Zn structure by XRD and showed no luminescence-emitting property by PL measurement, even proceeded by oxygen plasma. However, by changing evaporation source to amorphous SiO powder showed slightly luminescence-emitting. Furthermore, light emitting intensity became larger when films were stored in the air for 8 months. Latent fingerprint developed by source mixed of ZnO and SiO powders showed considerable luminescence intensity when firstly evaporated, which is possibly caused by defects of dioxasilirane and silylene. Finally, various of objects were selected to try to achieve development of latent fingerprint, and investigate the luminescence-emitting property as well as take pictures after excited by UV light. Results could be applied to forensic science.