Indian Institute of Technology Kanpur

Baquer Mazhari

Ankita Gangwar

Arjit Ashok

Technologies are generally described for a four-terminal, gate-controlled, thin-film thyristor device. The thyristor device may essentially be an n-type thin-film transistor (TFT) with an additional emitter terminal. The thyristor device may exhibit an S-shaped negative differential resistance (NDR) characteristic resulting from conductance modulation. The conductance modulation may be caused by formation of a secondary channel for current flow due to an inherent structure of the device. The secondary channel may be formed in a semiconductor area within the device, the semiconductor area including a hole transporting organic semiconductor layer (HTL) and an electron transporting organic semiconductor layer (ETL). A gate terminal of the thyristor device may further allow onset of NDR characteristics to be controlled and may allow the device to be switched off.

Four-terminal gate-controlled thin-film organic thyristor

A novel light-emitting device includes an organic thin-film structure that is merged with an organic light-emitting diode structure by utilizing a part of the electron accumulation layer in the organic thin-film transistor as a common electrode for each structure. The organic thin-film structure and the organic light-emitting diode structure each include an organic semiconductor that comprises a material in which hole mobility is greater in a bulk region of the material than electron mobility in the bulk region. The advantages of such a light-emitting device include less complex processing and a simpler pixel circuit structure in comparison to separately fabricating OTFT and OLED structures and subsequently interconnecting them to form a pixel. Furthermore, relative to a light-emitting transistor, some embodiments offer the advantage of a broader light emission area more suitable for use in display devices.

Organic thin film transistor merged with a light emitting diode using an accumulation layer as electrode

A thin film transistor (TFT) includes a hole transport layer having a first side and a second side and an electron transport layer having a first side and a second side. The first side of the electron transport layer is directly interfaced to the second side of the hole transport layer. The electron transport layer includes a material having greater ionization potential and greater electron affinity than the hole transport layer, thereby forming a hole barrier and an electron barrier at the junction between the electron transport layer and the hole transport layer. A channel in the TFT is created by current injected into the electron transport layer from a gate electrode rather than by an electrostatic field generated by voltage applied to the gate electrode. The accumulated charge density in the channel of the TFT can be significantly larger than what can be generated through field effect principle, therefore a much lower gate voltage is needed than in a conventional TFT.

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Kanpur, India

Baquer Mazhari