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 -