Premium
Correlation between growth orientation and growth temperature for bismuth tri‐iodide films
Author(s) -
Cuña A.,
Aguiar I.,
Gancharov A.,
Pérez M.,
Fornaro L.
Publication year - 2004
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.200410274
Subject(s) - bismuth , iodide , materials science , substrate (aquarium) , electrical resistivity and conductivity , thin film , analytical chemistry (journal) , deposition (geology) , grain growth , grain size , mineralogy , chemistry , composite material , nanotechnology , inorganic chemistry , metallurgy , paleontology , oceanography , engineering , chromatography , sediment , biology , geology , electrical engineering
This paper reports the growth of bismuth tri‐iodide thick films intended for direct and digital X‐ray imaging. Films were grown by the vertical physical vapor deposition method, onto glass substrates 2″x 2″ in size, with gold previously deposited as rear electrode. The film thickness was up to 33 μm (±5 %). Optical microscopy and SEM were performed on the films and grain size resulted to be up to 40 μm. A strong correlation was found between the microcrystals growth orientation and the growth temperature. At low temperatures, microcrystals grow with their c axis parallel to the substrate, whereas at higher temperatures, they grow with their c axis perpendicular to the substrate. The higher the growth temperature, the lower the dark current of the film, and the higher the resistivity, which was from 10 13 to 10 15 Ωcm. A sensitivity to X‐rays of 6.9 nC/R.cm 2 was measured irradiating the films with X‐rays from a mamographer. Film properties were correlated with the growth temperature, with previous results for bismuth tri‐iodide films and monocrystals and with data for films of alternative materials such as lead and mercuric iodide. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)