Transparent AMOLED display driven by split oxide TFT backplane

Abstract

We have developed stable and high performance etch-stopper amorphous indium-galliumzinc oxide thin-film transistor (TFT) by using split active oxide semiconductor. The amorphous indiumgallium-zinc oxide TFTs exhibit the mobility as high as over 70 cm 2 /Vs and the stable operation under positive bias temperature stress. In this work, we demonstrated a 4-in. transparent active-matrix organic light-emitting diode display using oxide TFT backplane with split active layer, where the gate driver is integrated.

Highly robust oxide TFT with bulk accumulation and source/drain/active layer splitting

“…The unique properties of oxide‐based semiconductors such as wide bandgap and high transparency also make novel applications possible. For example, a see‐through type transparent AMOLED can be realized using oxide based semiconductor . Using such types of displays, one can see the objects in the opposite side of the displays, and thus many interesting applications can be possible.…”

“…For example, a see-through type transparent AMOLED can be realized using oxide based semiconductor. [11][12][13][14] Using such types of displays, one can see the objects in the opposite side of the displays, and thus many interesting applications can be possible. Since the transparency of such displays mostly relies on the use of transmission area or highly transparent materials, high-resolution and high transparency displays cannot be obtained at the same time.…”

“…And, we reported the advantages of the split active layer used for etch‐stopper (E/S) oxide TFTs. The mobility can be over 70 cm 2 /Vs and the low sub‐threshold swing (SS) and there are stable under the bias, temperature, and mechanical stress . In addition, we reported that the micron size patterning (split) of source, drain, and gate electrodes as well as of the a‐IGZO semiconductor layer improves TFT robustness under mechanical bending strain .…”

“…The mobility can be over 70 cm 2 /Vs and the low sub-threshold swing (SS) and there are stable under the bias, temperature, and mechanical stress. 13,14 In addition, we reported that the micron size patterning (split) of source, drain, and gate electrodes as well as of the a-IGZO semiconductor layer improves TFT robustness under mechanical bending strain. 15,16 To prevent the extension of cracks in semiconductor and source/drain (S/D) electrode layer, split both electrodes and semiconductor can be used.…”

1.2: Invited Paper: Dynamic threshold voltage compensation IGZO‐GOA circuit for AMOLED display

“…However, the inhomogeneity of LTPS backplanes limit their use prospect in the field of TV displays [3]. Amorphous-indium-gallium-zincoxide (a-IGZO) TFTs have attracted much attention owing to their low process temperature, low off-leakage current and high uniformity [4]. Unfortunately, the threshold voltage and the mobility of a-IGZO TFTs would shift seriously when TFTs suffer positive bias temperature stress (PBTS) and negative bias temperature stress (NBTS).…”