A New Method on Response Speed of Uni-traveling-carrier Double

Heterojunction Phototransistor: Bilateral Incidence from the Base

Region

Liang Chen

1, a

School of Physics and Electronic Engineeing ,Taishan University, Taian, 271000 China

Keywords: Uni-traveling-carrier, high-responsivity, high-speed.

Abstract: In this paper, a new method to improve the response speed of an SiGe-based uni-traveling-carrier double

heterojunction phototransistor (UTC-DHPT) are illustrated. The detailed analysis show that bilateral

incidence from the base region has better performances than one incidence from the base region.

1 INTRODUCTION

The heterojunction phototransistor (HPT) can be

used in the front end of the optical receiver for opto-

electronic integrated circuits (OEICs). Now, most

photode-tectors (PDs) are based on III-V materials

due to the weak lightabsorption of Si. However, the

III-V-based PDs (Y. L. Liu et al, 2015; G. zang, et al,

2014; T. Ishibashi, et al, 1997) are hard to integrate on

Si and increase the cost of the hybrid circuits. In

order to overcome the drawback of the weak

photoabsorption process in Si material and the

problems in system integration of III-V-based PDs,

the Si–SiGe HPT with 850-nm absorption has been

demonstrated (W. J. Huo, et al, 2014; Z. Y. Jiang, et al,

2015). With the rapid development of modern

optoelectronic technology, photodetectors are

required to have high responsivity and speed as a

key component in optoelectronic systems. HPT

dectertor has become a research focus in the

photoelectric field in recent years. In 1997, Ishibashi

proposed a uni-traveling-carrier photodiode (UTC-

PD) detector in Japan to increase its responsivity and

speed. Recent Papers reported show that application

of uni-traveling-carrier into HPT detector will also

improve the HPT performance. (J. L. Polleux, et al,

2004) In this paper, the optical responsivity and high

frequency characteristics of uni-traveling-carrier

double heterojunction phototransistor (UTC-DHPT)

through bilateral incidence from the base region are

illustrated in detail and compared with traditional

UTC-DHPT through one incident from the base

region. The UTC-DHPT through bilateral incidence

from the base region obtained higher saturation

current, higher responsivity and higher response

speed.

2 DEVICE CHARACTERISTICS

AND DISCUSSION

The two-dimensional structure of SiGe UTC-DHPT

are shown in Fig. 1.

Figure 1. Two-dimensional device structure of UTC-

DHPT.

Chen, L.

A New Method on Response Speed of Uni-traveling-carrier Double Heterojunction Phototransistor: Bilateral Incidence from the Base Region.

DOI: 10.5220/0008868604130415

In Proceedings of 5th International Conference on Vehicle, Mechanical and Electrical Engineering (ICVMEE 2019), pages 413-415

ISBN: 978-989-758-412-1

413

(a) Bilateral incidence

(b) One incident

Figure 2. Two-dimensional device structure of UTC-

DHPT based on ATLAS.

Fig 2 shows the the incident way of the optical

beam, bilateral incidence area has the same as one

incident. The optical beam of 1.55μm across the

optical window is injected into the exposed base

with the collector biased at Vce = 2 V. The collect

current(IC) of bilateral incidence is higher than one

incident when light power increasing from 0.1 mW

to 0.25 mW as show in Fig 3 and Fig 4. Thus,

bilateral incidence obtained higher maximum

responsivity as light power increasing from 0.1 mW

to 0.25 mW.

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40

collect currentI(mA)

Light power（mW）

bilateral incidence

one incident

Figure 3. collector current of the bilateral incidence and

one incident as a function of with incident light power.

0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40

optical responsivity（A/W）

Light power (mW)

bilateral incidence

one incident

Figure 4. The optical responsivity of the bilateral

incidence and one incident as a function of light power.

ICVMEE 2019 - 5th International Conference on Vehicle, Mechanical and Electrical Engineering

414

0.0 0.5 1.0 1.5 2.0

0.00E+000

5.00E+009

1.00E+010

1.50E+010

2.00E+010

2.50E+010

(Hz)

Collector Current (mA)

bilateral incidence

one incident

Figure 5. Dependences of 𝑓𝑇 on 𝐼𝐶 of bilateral incidence

and one incident.

The 𝑓𝑇−𝐼c curves of the bilateral incidence and

one incident were extracted with V ce = 2𝑉, as the

Fig.5 shows. The maximum 𝑓𝑇 of bilateral

incidence reaches 2.5*1010Hz as collector current of

1mA, and the maximum 𝑓𝑇 of one incident is

1.1*1010Hz as collector current of 1.1mA. It is

apparent that 𝑓𝑇 of bilateral incidence is higher than

one incident.

3 CONCLUSIONS

In this paper, the saturation current, optical

responsivity and high frequency characteristics of

the UTC-DHPT with bilateral incidence from the

base region have been studied in detail. The results

show that UTC-DHPT with bilateral incidence from

the base region has a higher saturation current and

maximum optical response than one incident. The

collect current(IC) and maximum responsivity of

bilateral incidence is higher than one incident when

light power increasing from 0.1 mW to 0.25 mW.

Meantime, 𝑓𝑇 of bilateral incidence is higher than

one incident.

ACKNOWLEDGMENTS

This research was supported in part by the National

Nature Science Foundation of China (61604106) and

Shandong Provincial Natural Science Foundation

(ZR2014FL025).

REFERENCES

G. zang, et al., “Design and analysis of high speed and

high saturation uni-traveling-carrier photodetector,”

Acta Phys. Sin., vol.63, pp. 208502-1~208502-6,

Sep.2014.

J. L. Polleux, et al. “Optimization of InP-InGaAs HPT

gain: design of an opto-microwave monolithic

amplifier.” IEEE Trans TECHNIQUES on

Microwave Theory and Techniques, vol.52, pp. 871-

881, Mar.2004.

T. Ishibashi, et al., “High-speed response of uni-traveling-

carrier photodiodes,” Japanese journal of applied

physics, vol. 36, pp. 6263- 6268, Oct.1997.

W. J. Huo, et al., “Study on uni-traveling-carrier double

hetero-junction photo-transistor (UTC-DHPT)

photodetector,” Acta Physica Sinica, vol.62,

pp.228501-1~228501-10, Nov.2013.

Y. L. Liu et al., “Transparent, Broadband, Flexible, and

Bifacial-Operable Photodetectors Containing a Large-

Area Graphene–Gold Oxide Heterojunction.” ACS

nano, Vol.9, pp.5093-5103, May.2015.

Z. Y. Jiang, et al., “Analysis on high speed response of a

uni-traveling-carrier double hetero-junction

phototransistor,” Chin. Phys. B, vol.24, pp.048504-

1~0485045, Apr.2015.

A New Method on Response Speed of Uni-traveling-carrier Double Heterojunction Phototransistor: Bilateral Incidence from the Base

Region

415