TY - GEN
T1 - The geometry effect on threshold voltage of top-contact and bottom contact pentacene based thin film transistors
AU - Wang, Yu Wu
AU - Liu, De Zhi
AU - Hong, Ming Yue
AU - Cheng, Horng Long
PY - 2009/12/1
Y1 - 2009/12/1
N2 - In this article, we fabricated a series of different geometries for pentacene based thin film transistors (TFTs), including top contact (TC) and bottom contact (BC) configurations, to monitor variations in characteristics. The threshold voltage (Vth) in the saturation regime shifted toward a positive voltage, i.e., from 0.5, 3.2, 9.1, 12.1, and 19.5 V for the channel lengths 67, 47, 23, 19, and 15 μm, respectively, in BC TFTs. All of the TFTs were operated in depletion mode. However, the Vth in the linear regime shifted from -9.3, -9.0, -3.8, -1.8, and 1.5 V for the same devices. Most of the TFTs in the linear regime were operated in enhanced mode. The phenomenon is believed to be strongly correlated with the longitudinal electric field (VDS/L). The high VDS induces a high carrier injection, which makes the pentacene TFTs behave like a depletion type transistor. This assumption is evidenced by the low carrier injection with small VDS results. The device configuration and space charge region must be discussed in more detail. Furthermore, the field effect mobility variation and structure configuration effect is discussed in more detail within the full manuscript.
AB - In this article, we fabricated a series of different geometries for pentacene based thin film transistors (TFTs), including top contact (TC) and bottom contact (BC) configurations, to monitor variations in characteristics. The threshold voltage (Vth) in the saturation regime shifted toward a positive voltage, i.e., from 0.5, 3.2, 9.1, 12.1, and 19.5 V for the channel lengths 67, 47, 23, 19, and 15 μm, respectively, in BC TFTs. All of the TFTs were operated in depletion mode. However, the Vth in the linear regime shifted from -9.3, -9.0, -3.8, -1.8, and 1.5 V for the same devices. Most of the TFTs in the linear regime were operated in enhanced mode. The phenomenon is believed to be strongly correlated with the longitudinal electric field (VDS/L). The high VDS induces a high carrier injection, which makes the pentacene TFTs behave like a depletion type transistor. This assumption is evidenced by the low carrier injection with small VDS results. The device configuration and space charge region must be discussed in more detail. Furthermore, the field effect mobility variation and structure configuration effect is discussed in more detail within the full manuscript.
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U2 - 10.1117/12.826072
DO - 10.1117/12.826072
M3 - Conference contribution
AN - SCOPUS:77955676295
SN - 9780819477071
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Organic Field-Effect Transistors VIII
T2 - Organic Field-Effect Transistors VIII
Y2 - 3 August 2009 through 5 August 2009
ER -