Yukihisa Kusuda

Two-Phase Drive Self-Scanning Light-Emitting Device (SLED) Using Coupling Diodes

The self-scanning light-emitting device (SLED) is expected to become a new key device for two-dimensional optical information processing, because the light-emitting ON-states of the SLED are automatically transferred by input clock pulses, and the optical pulses can start the transfer action from any elements. It will be important to decrease the number of transfer clock lines in order to realize the highly packed two-dimensional integrated SLED. Therefore, we propose the two-phase drive SLED using coupling diodes and demonstrate its operation. It has a wide operating margin as well as 10 MHz as the maximum transfer frequency.

The Dependence of Field Effect Mobilities on Substrate Temperature for Amorphous Silicon Deposition for Amorphous Silicon Thin Film Transistors

We evaluated the field effect mobility ( µFE) for a-Si TFTs at different temperatures for a-Si deposition (Tsub). The µFE showed a maximum in the temperature range of 200~250°C. We estimated the tail localized state distribution of the a-Si films for each Tsub value from theoretical curves modified by the measurement temperature dependence of µFE. The result of the fittings showed that the a-Si tail localized state was suppressed in the Tsub range 200~250°C.

Proposal of self-scanning light emitting device (SLED)

A novel functional optoelectronic device, the self-scanning light-emitting device (SLED), is proposed. The SLED consists of light-emitting thyristors whose turn-on voltages interact with each other, and the light-emitting element is automatically transferred by input clock pulses. GaAs SLED operation was demonstrated using four phase transfer clock pulses, and a maximum transfer rate of 3 MHz was obtained. It is suggested that the SLED is promising for optical computing and optical interconnection technology with high-density integration.<<ETX>>

Integrated self-scanning light-emitting device (SLED)

The fabrication of monolithically integrated self-scanning light-emitting device (SLED) on a GaAs substrate and its performance are described. The SLED consists of integrated light-emitting thyristors whose turn-on voltages interact with each other through coupling diodes or resistors. Light-emitting states are automatically transferred by input clock pulses without using external shift registers. The resistors are made of a Cr-SiO cermet film, and the coupling diodes are made in part with p-n layers of thyristors. The integrated SLED is fabricated in eight photolithographic steps. High-speed operation, more than 10 MHz, can be achieved due to its simple structure and high-density packaging. It is expected that this SLED will be a key device in future large-scale optoelectronic integrated circuits. >

Emitter probe model for plasma coupling phenomenon in plasma-coupled device

Recently, to stabilize the operation of plasma-coupled device shift registers (PCD-SR), a emitter probe structure mounted on the PCDs emitter has been invented. The probe protrudes in the anti-transfer direction, and serves to pick up the lowered potential of the substrate around the preceding ON-PCD element. In this paper, the effect of the probe structure is investigated in detail, and a new quantitative probe model for the plasma coupling phenomenon is proposed. Especially with this model, it is considered that the deformation phenomenon of the Conductivity Modulation Region (CMR) induced by the probe current injection increases the coupling resistance. Using this model, the theory of the operation of the PCD-SR with the emitter probe structure is developed, and it is confirmed that this theory explains the experimental results.

Proposal of Integrated Light Emitting Device Array with Shift Register

We propose two types of new integrated light-emitting device arrays with a shift register for the photo-printer head. The proposed device arrays consist of a self-scanning light-emitting device (SLED) as a shift register and light-emitting thyristors for printing. One of the proposed device arrays, which has 12 bits and a 62.5-µm-pitch thyristor array, was fabricated and demonstrated. It has a wide operating margin of about 2 V, and has a maximum transfer frequency of 10 MHz.

A Quick Computation of Potential Distribution in a Highly Conductivity-Modulated Semiconductor and its Application to PCD Devices

The plasma-coupled device (PCD), which is a bipolar type functional device, has been applied to various image sensors. However, the PCD patterns cannot be designed by computer simulation because of the difficulty in calculating three-dimensional potential distribution in a highly-injected, highly conductivity-modulated semiconductor body. This letter proposes a new but practical simulation method in which some simple assumptions are employed. It is shown that the shape of the potential distribution and the conductivity modulation region around the ON-element of the PCD are consistent with the experimental observation.