RT Journal Article T1 Nanoscopic study of ZnO films by electron beam induced current in the scanning tunneling microscope A1 Urbieta Quiroga, Ana Irene A1 Fernández Sánchez, Paloma A1 Piqueras De Noriega, Francisco Javier A1 Vasco, E. A1 Zaldo, C. AB Scanning tunnelling microscopy and spectroscopy have been used to characterize electrically active grain boundaries in pulsed laser deposited ZnO films with grain sizes in the range 216-500 nm. The p-type behaviour at the boundary is evidenced by local STM conductance spectra, which reveal boundaries with a n-p-i-p-n structure. in addition, local differential conductance measurements show higher surface band gap at the grain boundaries than in the grain interior, which is related to the space charge at the boundaries. The beam induced current mode of the STM has been used to image electrically active grain boundaries with a resolution of few nanometers in the different films. It is demonstrated that in some of the small grains the space charge region extends to the whole grain area so that no electrical barrier can be related to the grain boundary. PB Natl Inst Optoelectronics SN 1454-4164 YR 2004 FD 2004-03 LK https://hdl.handle.net/20.500.14352/51146 UL https://hdl.handle.net/20.500.14352/51146 NO © Natl Inst Optoelectronics.This work has been supported by MCYT (Project MAT2000-2119) and by CAM (project 07N/0004/2001) NO MCYT NO CAM DS Docta Complutense RD 6 may 2025