Amorphous indium-gallium-zinc-oxide visible-light phototransistor with a polymeric light absorption layer

Zan, Hsiao‐Wen; Chen, Wei-Tsung; Hsueh, Hsiu-Wen; Kao, Sung‐Shuo; Ku, M. L.; Tsai, C. C.; Meng, Hsin‐Fei

doi:10.1063/1.3517506

Cited by 87 publications

(60 citation statements)

References 8 publications

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“…Phototransistors using only a BHJ channel have been shown to exhibit broad absorption spectra 34 , but the disordered nature of BHJs makes it difficult to approach mobilities of 1 18,29 and various metal oxides 35 operate as phototransistors, but their photonic performance is limited by low absorption outside the ultraviolet region due to their wide bandgaps. On the other hand, the properties of these devices can be combined by forming a heterojunction between a good absorber that efficiently generates electron-hole pairs and high-mobility semiconductor to rapidly transport the carriers out of the device 19,28,36,37 . Organic BHJs and high-mobility organic heterostructures have been demonstrated for light-emitting transistors 38,39 , but no studies have been carried out on photodetectors such as phototransistors, to the best of our knowledge.…”

Section: Resultsmentioning

confidence: 99%

Charge-integrating organic heterojunction phototransistors for wide-dynamic-range image sensors

2017

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Section: Resultsmentioning

confidence: 99%

Charge-integrating organic heterojunction phototransistors for wide-dynamic-range image sensors

2017

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“…No noticeable hysteresis effect was observed, indicating that the metal capping does not generate additional defect states. 8 An inverter comprised of an enhancement-mode a-IGZO TFT ͑Ti back gate͒ to serve as a switch and a depletion-mode a-IGZO TFT ͑Ca back gate͒ to serve as the load is demonstrated as shown in the inset of Fig. 4.…”

Section: Dielectricmentioning

confidence: 99%

Dual gate indium-gallium-zinc-oxide thin film transistor with an unisolated floating metal gate for threshold voltage modulation and mobility enhancement

Zan

Chen

Yeh

et al. 2011

Applied Physics Letters

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In this study, we propose a floating dual gate (FDG) indium-gallium-zinc-oxide (IGZO) thin film transistor (TFT) with a floating metal back gate that is directly contact with IGZO without a dielectric layer. The floating back gate effect is investigated by changing the work function (ϕ) of the back gate. The FDG IGZO TFT exhibits an improved field-effect mobility (μ), unchanged subthreshold swing (SS), high on/off current ratio, and a tunable threshold voltage ranged (Vth) from −5.0 to +7.9 V without an additional back gate power supply.

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“…High electrical stability is also critical for IGZO field effect sensors used for detecting gases, 6 temperature, 7 light, 8 or for deoxyribonucleic acid. 9 For these reasons the bias stress stability of IGZO-TFTs has been intensely investigated where effects of composition, process temperature, process conditions, gate dielectric, back channel passivation, and many other factors have been evaluated.…”

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confidence: 99%

Role of Self-Assembled Monolayers on Improved Electrical Stability of Amorphous In-Ga-Zn-O Thin-Film Transistors

Flynn

Motley

et al. 2014

ECS J. Solid State Sci. Technol.

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Self-assembled monolayers (SAMs) have been used to improve both the positive and negative bias-stress stability of amorphous indium gallium zinc oxide (IGZO) bottom gate thin film transistors (TFTs). N-hexylphosphonic acid (HPA) and fluorinated hexylphosphonic acid (FPA) SAMs adsorbed on IGZO back channel surfaces were shown to significantly reduce biasstress turn-on voltage shifts compared to IGZO back channel surfaces with no SAMs. FPA was found to have a lower surface energy and lower packing density than HPA, as well as lower biasstress turn-on voltage shifts. The improved stability of IGZO TFTs with SAMs can be primarily attributed to a reduction in molecular adsorption of contaminants on the IGZO back channel surface and minimal trapping states present with phosphonic acid binding to the IGZO surface. 10-15Proposed mechanisms for bias stress threshold voltage (V th ) shifts include electron trapping at the semiconductor/dielectric interface, electron injection into the dielectric, or formation of sub-band gap states in the bulk of films. It has also been suggested that adsorbed species (e.g., O 2 and H 2 O) on the back channel of the IGZO-TFTs can be the dominant mechanism for device instability, by providing acceptor or donor states or through field induced adsorption or desorption of these species. [17][18][19][20] For example, molecular oxygen can form a depletion layer at the back channel surface through electron acceptor states, while absorbed water can form an accumulation layer at the back channel surface through electron donor states.A depletion layer results in a positive V th shift, whereas an accumulation layer results in a 4 negative V th shift. Recently it has been demonstrated that dense passivation layers 21 or selfassembled monolayers (SAMs) 22 on IGZO-TFT back channels can significantly minimize these threshold voltage shifts. A potential benefit of using SAMs for surface passivation is that one can obtain well controlled chemistries at the back channel interface, even when using polymeric dielectrics for flexible electronic applications or integrating polymeric sensing layers.Herein we investigate the use of n-hexylphosphonic acid (n-HPA) and (3,3,4,4,5,5,6,6,6- IGZO-TFT test structures were fabricated using a heavily p-doped Si substrate as the gate and thermally grown SiO 2 (100 nm) as the gate dielectric. Substrates were cleaned prior to deposition of IGZO with acetone, isopropyl alcohol, and DI water. Amorphous IGZO films (~50 nm thick) were deposited using RF magnetron sputter deposition with a 3 in. IGZO target (molar composition: In 2 O 3 :Ga 2 O 3 :ZnO), 100W RF power, ~4 mTorr chamber pressure, and 20 sccm flow rate with a 1:19 (O 2 :Ar) ratio. IGZO active layers were patterned using a shadow mask 5 during deposition, and the films were subsequently annealed in air to 300 °C. Source and drain electrodes were patterned using a shadow mask during thermal evaporation of Al (~500 nm thick) giving a W/L ratio of 1000 m/100 m. Back channel surface passivation using SAMs was ...

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Amorphous indium-gallium-zinc-oxide visible-light phototransistor with a polymeric light absorption layer

Cited by 87 publications

References 8 publications

Charge-integrating organic heterojunction phototransistors for wide-dynamic-range image sensors

Charge-integrating organic heterojunction phototransistors for wide-dynamic-range image sensors

Dual gate indium-gallium-zinc-oxide thin film transistor with an unisolated floating metal gate for threshold voltage modulation and mobility enhancement

Role of Self-Assembled Monolayers on Improved Electrical Stability of Amorphous In-Ga-Zn-O Thin-Film Transistors

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