title: Ultrafast dual-drifting layer uni-traveling carrier photodiode with high saturation current.
abstract: A novel backside-illuminated mesa-structure dual-drifting layer (DDL) uni-traveling-carrier photodiode (UTC-PD) is reported to demonstrate high-power performance at sub-THz frequencies. The DDL structure consists of a velocity overshoot layer and a velocity saturation layer, formed by inserting a 20 nm p-type cliff layer into the thick depletion region. In the overshoot layer, photo-generated electrons drift at overshoot velocity under the carefully designed electric field profile, thus resulting in a short electron transit time. The saturation layer serves as a voltage sacrificing layer to enable high bias voltage operation, which leads to alleviated load voltage swing effect, as well as improved saturation performance. Our DDL UTC-PD exhibits a 3-dB bandwidth of 106 GHz with a responsivity of 0.17 A/W under a wide bias voltage range from 4 to 8 V. The photocurrent reaches up to 28 mA, corresponding to an output power of 7.3 dBm at 105 GHz.
authors.forename: Jin
authors.initials: J
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Xiong
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
authors.forename: Changzheng
authors.initials: C
authors.lastname: Sun
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Zhibiao
authors.initials: Z
authors.lastname: Hao
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Han
authors.forename: Lai
authors.initials: L
authors.lastname: Wang
authors.forename: Hongtao
authors.initials: H
authors.lastname: Li