Ultrasensitive Ferroelectric Semiconductor Phototransistors for Photon‐Level Detection

Abstract

Low-light-level photodetections are highly desired in the fields of astronomy and quantum information. However, the existing techniques suffer from high operation voltages and complexity of fabrication, which reduces its compatibility with complementary metal oxide semiconductors (CMOS) based read-out circuit and prevent the use of imaging. Here, a low-light-level phototransistor that employs a photo-induced ferroelectric reversal mechanism in a ferroelectric semiconductor channel: α-In 2 Se 3 is demonstrated. It shows a record-low noise-equivalent power of 7.9 × 10 −22 W Hz −1/2 , a recordhigh specific detectivity of 6.34 × 10 17 Jones, and sensitivity approaching 20 photons in a photon-counting mode, and fast time response of 260 µs/50 ns in the rise/decay period. It also works as an optoelectronic memory with an on/off ratio of 2.9 × 10 5 , retention of longer than 10 years, and endurance of more than 10 6 cycles. Due to its high performance, simple architecture, and small operation voltage, the phototransistor provides a feasible platform for new-generation low-light-level image sensors.

An all-two-dimensional Fe-FET retinomorphic sensor based on the novel gate dielectric In2Se3−xOx

“…† In this all-2D Fe-FET photodetector, the on/off current ratio and specific detectivity are comparable to the best reported 2D ferroelectric material photodetectors, as shown in Table S1 † of the ESI. 15,19,21,48 More interestingly, under positive gate voltage, a large dark current and photocurrent retention properties after the light is turned off were found, as shown in Fig. 5(a), which could act as the excitatory postsynaptic current (EPSC) for an artificial synaptic device.…”

Multifunctional Crystalline InGaSnO Phototransistor Exhibiting Photosensing and Photosynaptic Behavior Using Oxygen Vacancy Engineering

“…[43] It can be extracted from PR = I on −I off P in * A , [22] where P in is the power density of incident light, and A is the active area (8 × 4 μm 2 ). [22] Detectivity is an indicator of the ability to detect weak light signal. [1] It can be extracted from responsivity using D * = PR √ 2qJ dark…”

“…The −3 dB point (f −3dB ), defining photoresponse of 50% of I 0 , is 2400 Hz. [22,27] The transient photocurrents when switching at frequencies of 1000, 1200, 1800, and 2500 Hz are shown in Figure S9 in the Supporting Information.…”

“…When we define rising and falling times as the time taken to increase the photocurrent from 10% to 90% and the decay time from 90% to 10%, the rising and falling times are 404 and 335 µs, respectively. [ 5,22 ] Even when switching at 2000 Hz as shown in Figure 3b, it clearly shows on/off behavior with fast response and good repeatability. However, it does not turn off completely and shows the dark current of about 128 nA.…”

Integration of image preprocessing and recognition functions in an optoelectronic coupling organic ferroelectric retinomorphic neuristor

“…[33][34][35][36][37] The realization of light-modulated ferroelectric polarization reversal brings a wealth of optoelectronic characteristics that can be used to simulate the biological function of bipolar cells in the retina and the synaptic connections of the visual cortex in a natural way, thus enabling a more advanced neuromorphic MVS. [38][39][40][41][42][43][44][45][46] Herein, organic ferroelectric retinomorphic neuristors are constructed using ultrathin ferroelectric polymer films and smallmolecule semiconductors. The preprocessing function of bipolar cells and the recognition of the visual cortex are achieved in a single device using an optoelectronic coupling modulated ferroelectric polarization reversal.…”