Blue-enhanced thin-film photodiode for dual-screen x-ray imaging

• Main Author: Vygranenko, Yuri
• Publication Date: 2009
• Other Authors: Sazonov, A., Heiler, G., Tredwell, T., Vieira, Manuela, Nathan, Arokia
• Format: Article
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10400.21/1268
• topic: Current density; p-i-n photodiodes; Thin films; X-ray imaging

This article reports on a-Si:H-based low-leakage blue-enhanced photodiodes for dual-screen x-ray imaging detectors. Doped nanocrystalline silicon was incorporated in both the n- and p-type regions to reduce absorption losses for light incoming from the top and bottom screens. The photodiode exhibits a dark current density of 900 pA/cm(2) and an external quantum efficiency up to 90% at a reverse bias of 5 V. In the case of illumination through the tailored p-layer, the quantum efficiency of 60% at a 400 nm wavelength is almost double that for the conventional a-Si:H n-i-p photodiode.