In this work we report on the design, fabrication, electrical characterization and sensing tests of new silicon bipolar junction phototransistors, coated by Zn-(heptiloxy)-TPP. The finger-shaped emitter/base junction has been proved to enhance the responsivity in the blue spectral region with respect to the standard fully implanted detector (0.24A/W and 0.14A/W respectively at 5 V reverse bias). This effect has been experimentally tested in reverse biased E/B junction and, even though the phototransistor is operated with floating base, slightly forward biasing the E/B junction, this improvement in responsivity was still observed. The new transducers exhibit a beta current gain higher than 150 and were employed to detect ethanol concentrations down to 300ppm.
Finger emitter/base bipolar junction phototransistors for optical gas sensing in the blue spectral region
Tibuzzi, Arianna;Dalla Betta, Gian Franco;Piemonte, Claudio;Ficorella, Francesco;Soncini, Giovanni
2004-01-01
Abstract
In this work we report on the design, fabrication, electrical characterization and sensing tests of new silicon bipolar junction phototransistors, coated by Zn-(heptiloxy)-TPP. The finger-shaped emitter/base junction has been proved to enhance the responsivity in the blue spectral region with respect to the standard fully implanted detector (0.24A/W and 0.14A/W respectively at 5 V reverse bias). This effect has been experimentally tested in reverse biased E/B junction and, even though the phototransistor is operated with floating base, slightly forward biasing the E/B junction, this improvement in responsivity was still observed. The new transducers exhibit a beta current gain higher than 150 and were employed to detect ethanol concentrations down to 300ppm.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
