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The next great telecom revolution phần 10

LEPs có thể để giảm chi phí sản xuất thông qua việc sử dụng vật liệu hiệu quả. "LEPs cung cấp tất cả những lợi thế của công nghệ phân tử nhỏ như tiêu thụ lowpower và ổ điện áp thấp," ông Joe Constance, một nhà phân tích kỹ thuật Insights, một nghiên cứu công nghệ công ty đặt tại San Antonio, Texas. | 206 THE CRITICAL LAST INCH INPUTAND OUTPUT TECHNOLOGIES materials LEPs are able to reduce manufacturing cost through effective material utilization. LEPs offer all the advantages of small-molecule technology such as low-power consumption and low-drive voltages says Joe Constance an analyst at Technical Insights a technology research company located in San Antonio Texas. LEP devices can generate sharp light output or resolution and can be fabricated cost effectively in high-pixel density configurations he adds. Efficient control over structural order in LEPs is required to have an edge over traditional liquid crystal displays. In this regard polymers that have different band gaps may prove to be a key factor in outplaying competing technologies. Emission of red green or blue light is possible with different bands making full-color displays with conductive LEPs commercially viable. Intense research in this area has enabled poly-phenylene vinylene PPV to emit blue light by interrupting conjugation in the polymer with nonconjugated units. Attachment of alkoxy side groups to the phenylene rings of the PPV enables red light production. A full-color polymer-based display requires pixellating the colors through the combination of different conducting polymers with varying band gaps. The color emitted from the blend will depend on the amount of voltage applied which increases with the band gap. An alternative route would be to use whitelight-emitting diodes to create a microcavity the length of which determines the color of the emitted light. Apart from varying band gaps polymer-based light-emitting diodes also face the challenge of increasing operating lifetimes to at least 20 000 hours to popularize commercial usage. When the luminance intensity of the device decreases to 70 percent of the original value it is considered the actual end of life as opposed to 50 percent referenced for display applications. In the area of LEPs significant research has been in progress to .