Effects of TFT mobility variation in the threshold voltage compensation circuit of the OLED display

Figures & data

Figure 1. (a) PMOS 6T1C Vth compensation pixel circuit in Ref. [1]; (b) its timing diagram.

Figure 2. (a) Initializing phase, (b) programing phase, and (c) emission phase of the 6T1C circuit operation process.

Figure 3. Waveforms of the gate and source voltages of M1 TFT during the operation phases for the different mobility cases.

Table 1. RPI poly-Si TFT model parameters for spice simulation.

Parameter	Value	Parameter	Value	Parameter	Value
TNOM	27	TOX	1E−7	VON	0
VTO	−0.57	VFB	0	CGSO	3E−10
DVT	0	VKINK	10	CGDO	3E−10
MU1	1E−3	MMU	2.6	MUS	1
MU0	50	MK	1.3	BT	1E−7
RD	1.5E+3	RS	1.5E+3	DELTA	4
BLK	1.9E−6	DD	9E−8	ETA	3.6
DG	2E−7	EB	0.55	ASAT	1
I0	6	I00	150	LASAT	0
AT	3E−9	DASAT	0	RSH	1.5E+3
LKINK	1.9E−6

Figure 4. Transfer characteristics of the TFT models for (a) high-field mobility (MU0) doubling, (b) low-field mobility (MU1) doubling, (c) subthreshold mobility (MUS) doubling, and (d) all the mobilities’ (MU0, MU1, and MUS) doubling when V_DS = −10 V and TFT’s W/L = 2 μm/10 μm.

Figure 5. Effects of all the mobilities’ doubling on the programed |V_GS.M1| values, and resultant OLED currents vs. the various target currents.

Figure 6. Different effects of the programed |V_GS.M1| decrease on the OLED currents for various target currents: (a) 1 nA; (b) 10 nA; and (c) 100 nA.

S.H. Jang, B.T. Son, S.H. Choi, D.J. Kim, G.S. Kim and M.H. Yoo, SID Symp. Dig. Tech. Pap. 47, 1162 (2016). doi: 10.1002/sdtp.10856

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