Graphene quantum dots modulated solution‐derived InGaO thin‐film transistors and stress stability exploration
Xiaofen Xu, Gang He, Leini Wang, Wenhao Wang, Xiaoyu Wu
Abstract
Abstract Graphene quantum dots (GQDs) doped InGaO (IGO) thin film transistors (TFTs) have been fabricated based on solution‐driven ZrO x as gate dielectrics. Compare to pure IGO TFTs, superior electrical performance of the GQDs‐IGO TFTs can be achieved by adjusting the doping concentration. It has been demonstrated that GQDs‐modified IGO TFTs devices with GQDs doping content of 0.3 mg·ml −1 have the optimized performances, including field‐effect mobility ( μ FE ) of 22.02 cm 2 ·V –1 ·s −1 , on/off current ratio ( I on / I off ) of 7.06 × 10 7 , subthreshold swing (SS) of 0.09 V⋅dec −1 , hysteresis of 0.04 V and interfacial trap states ( D it ) of 1.03 × 10 12 cm −2 . In addition, bias stress and illumination stress tests have been performed and excellent stability has been achieved for optimized GQDs‐IGO‐TFTs. The GQDs‐IGO TFTs device showed smaller threshold voltage shift of 0.12 and 0.04 V under positive bias stress (PBS) test and negative bias stress (NBS) test for 3600 s, respectively. And it showed smaller threshold voltage shift of 0.27 and 0.34 V for red light under the PBS and NBS test for 3600 s, respectively. Meanwhile, it showed smaller threshold voltage shift of 0.20 and 0.22 V for green light under PBS and NBS test for 3600 s, respectively. It also showed smaller threshold voltage shift of 0.17 and 0.12 V for blue under the positive bias illumination stress (PBIS) test and negative bias illumination stress (NBIS) test for 3600 s, respectively. Low‐frequency noise (LFN) characteristics of GQDs‐IGO/ZrO x TFTs indicated that the noise source came from the fluctuations in mobility. Finally, a low voltage resistor‐loaded unipolar inverter has been built based on GQDs‐IGO/ZrO x TFT, demonstrating good dynamic response behavior and a maximum gain of 7.4. These experimental results have suggested that solution‐processed GQDs‐IGO/ZrO x TFT may envision potential applications in low‐cost and large‐area electronics.