TY - JOUR
T1 - Low-dark-current heterojunction phototransistors with long-term stable passivation induced by neutralized (NH4)2S treatment
AU - Chiu, Shao Yen
AU - Chen, Hon Rung
AU - Chen, Wei Tien
AU - Hsu, Meng Kai
AU - Liu, Wen Chau
AU - Tsai, Jung Hui
AU - Lour, Wen Shiung
PY - 2008/1/18
Y1 - 2008/1/18
N2 - To investigate the effects of surface leakage on the temperature-dependent dark and optical performance of a heterojunction phototransistor (HPT), three sets of HPTs were prepared. They were unpassivated (HPT A), passivated with diluted (NH4)2S (HPT B), and passivated with neutralized (NH4)2S (HPT C). Passivation treatment successfully suppresses surface-defect-induced effects. The passivated HPTs exhibit a reduced dark current and an enhanced signal-to-noise ratio (SNR). HPT A exhibits a room-temperature collector dark current (ICdark) of 0.59 nA at a VCE of 1V, while those of HPTs B and C are 0.03 and 0.89pA, respectively. The room-temperature SNR values for HPTs A, B, and C at a P in of 8.3 (107.6) nW are 5.9 (42), 59 (91), and 91 (122) dB, respectively. After a three-week air exposure, the room-temperature SNR at a Pin of 107.6 nW decreases to 25 (67) dB for HPT A (B), while it is 116 dB for HPT C. The decrease for HPT C is only 6 dB. A long-term stable passivation with good thermal stability has been achieved by neutralized (NH4)2S treatment.
AB - To investigate the effects of surface leakage on the temperature-dependent dark and optical performance of a heterojunction phototransistor (HPT), three sets of HPTs were prepared. They were unpassivated (HPT A), passivated with diluted (NH4)2S (HPT B), and passivated with neutralized (NH4)2S (HPT C). Passivation treatment successfully suppresses surface-defect-induced effects. The passivated HPTs exhibit a reduced dark current and an enhanced signal-to-noise ratio (SNR). HPT A exhibits a room-temperature collector dark current (ICdark) of 0.59 nA at a VCE of 1V, while those of HPTs B and C are 0.03 and 0.89pA, respectively. The room-temperature SNR values for HPTs A, B, and C at a P in of 8.3 (107.6) nW are 5.9 (42), 59 (91), and 91 (122) dB, respectively. After a three-week air exposure, the room-temperature SNR at a Pin of 107.6 nW decreases to 25 (67) dB for HPT A (B), while it is 116 dB for HPT C. The decrease for HPT C is only 6 dB. A long-term stable passivation with good thermal stability has been achieved by neutralized (NH4)2S treatment.
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U2 - 10.1143/JJAP.47.35
DO - 10.1143/JJAP.47.35
M3 - Article
AN - SCOPUS:38549177407
SN - 0021-4922
VL - 47
SP - 35
EP - 42
JO - Japanese journal of applied physics
JF - Japanese journal of applied physics
IS - 1
ER -