Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Be-doped ZnO thin-film transistors and circuits fabricated by spray pyrolysis in air
AU - Thomas, Stuart
AU - Adamopoulos, George
AU - Anthopoulos, Thomas
PY - 2013/9
Y1 - 2013/9
N2 - We report the fabrication of zinc oxide (ZnO) thin film transistors (TFTs) and simple integrated circuits by spray pyrolysis, and examine the role of beryllium (Be) as a dopant. Doping is achieved through addition of Be-acetylacetonate intothe parent Zn-acetate precursor solution followed by film deposition through spray pyrolysis. The microstructural properties of as-grown Be-ZnO films with different dopant concentrations are investigated using a combination of atomicforce microscopy and x-ray diffraction techniques, which show the formation of polycrystalline films. Introduction of Be is found to impact the degree of crystallinity of ZnO films where a dramatic decrease in the average grain size is observed with increasing Be concentration. To assess the effects of Be-doping onthe electrical properties of ZnO films we have fabricated Be-ZnO based TFTs using different doping concentrations. The average electron mobility calculated from these transistors is on the order of ~2 cm2V-1s-1 with the threshold voltage (VTH) exhibiting a strong dependence on Be concentration. The ability to control Vth through the introduction of Be has been exploited for thefabrication of unipolar inverters with symmetric trip-voltages and good noise margins.
AB - We report the fabrication of zinc oxide (ZnO) thin film transistors (TFTs) and simple integrated circuits by spray pyrolysis, and examine the role of beryllium (Be) as a dopant. Doping is achieved through addition of Be-acetylacetonate intothe parent Zn-acetate precursor solution followed by film deposition through spray pyrolysis. The microstructural properties of as-grown Be-ZnO films with different dopant concentrations are investigated using a combination of atomicforce microscopy and x-ray diffraction techniques, which show the formation of polycrystalline films. Introduction of Be is found to impact the degree of crystallinity of ZnO films where a dramatic decrease in the average grain size is observed with increasing Be concentration. To assess the effects of Be-doping onthe electrical properties of ZnO films we have fabricated Be-ZnO based TFTs using different doping concentrations. The average electron mobility calculated from these transistors is on the order of ~2 cm2V-1s-1 with the threshold voltage (VTH) exhibiting a strong dependence on Be concentration. The ability to control Vth through the introduction of Be has been exploited for thefabrication of unipolar inverters with symmetric trip-voltages and good noise margins.
KW - High electron mobility
KW - thin-film transistors (TFTs)
KW - threshold voltage VTH control
KW - zinc oxide (ZnO)
U2 - 10.1109/JDT.2012.2222346
DO - 10.1109/JDT.2012.2222346
M3 - Journal article
VL - 9
SP - 688
EP - 693
JO - Journal of Display Technology
JF - Journal of Display Technology
SN - 1551-319X
IS - 9
ER -