Subhradeep Pal

In this work, we have experimentally fabricated a MoSe2/Bi2Se3-based type-II van der Waals (vdW) heterojunction photodetector (PD) suitable for detecting optical signals between 400 and 1000 nm. This PD shows excellent performance metrics such as a peak responsivity of 13.35 A/W and a detectivity of 5.7 × 1013 Jones at 400 nm. Also, the fabricated PD exhibited an ultrahigh external quantum efficiency of 4038% at 400 nm with rise and fall times of 105 and 166 ms, respectively. The built-in potential at the heterojunction facilitated excellent separation and transport of the photogenerated electron–hole pairs through suitable energy band diagrams. Also, various Schottky diode parameters of the device have been extracted from the measured I–V characteristics. Using the modeled parameters, I–V characteristics were redrawn and compared with the measured values. Between 0 and 5 V, the modeled I–V characteristics showed minimum and maximum errors of 0.57% and 6.21%, respectively.

This article reports a resistive chip-enabler logic inverter and an active-low 2 : 1 multiplexer based on Ag/SnO_2−x/ITO structured pressure-sensitive memristive devices for in-memory computing applications.

A high-performance flexible organic photodetector (OPD) with broad-spectrum capabilities utilizing a high-mobility conjugated polymer P-TZTZ is demonstrated. Using the OPD, a visible lightwave communicating link is also exhibited.

This article reports an organic/inorganic hybrid wideband photodetector (PD) made of a topological insulator (TI), Bi2Se3, and a donor-acceptor covalent polymeric framework (CPF) material (PDI-Tz) on a p-type Si substrate. Due to the formation of a strong type-II heterojunction between the CPF and TI, remarkably low dark current levels are expected. The fabricated PD exhibited a broadband photodetection capability ranging between 400 and 1100 nm with a peak responsivity and detectivity of 11.91 A/W and $2.51\times 10{^{{15}}}$ Jones at 400 nm. In addition, the PD offered an ultrahigh external quantum efficiency (EQE) of 3457% at 400 nm. Furthermore, stable time-dependent photoresponse characteristics with millisecond-order transient metrics indicate the efficacy of the fabricated PD.

In this paper, a surface plasmon resonance assisted hybrid photodetector (PD) made of a low bandgap covalent polymeric framework material is experimentally demonstrated. The PD demonstrated a broadband photodetection capability ranging between 350 and 1550 nm with subsecond transients. The fabricated hybrid PD offered a remarkable responsivity and external quantum efficiency of 42.87 A/W and 11 873% at 410 nm, respectively. The peak detectivity is recorded to be 7.43×1013 Jones at 400 nm. Up to 1550 nm, the hybrid PD offered a responsivity > 0.4 A/W, thereby showcasing its efficacy even for the near-infrared signals. The time-dependent photoresponse study estimated the rise time and fall time of the fabricated PD to be approximately 0.31 and 0.22 s, respectively.

In this article, we report the development of a wideband visible photodetector (PD) based on a heterostructure composed of ReS2 and MoSSe, constructed on a p-type silicon substrate. The architecture of the device consists of Al and Ag serving as the two electrodes for the PD. The fabricated PD exhibited remarkable photodetection capabilities spanning from 400 to 750 nm, with its peak responsivity reaching 4.42 A/W at 410 nm. The PD achieved a highest measured specific detectivity of 8.51 $\times$ 10 ¹⁰ Jones and an external quantum efficiency (EQE) of 13.37%. In terms of transient performance, the PD demonstrated a rise time of 0.3 s and a fall time of 0.22 s. We also integrated this fabricated PD into a 30 cm long on–off keying (OOK) modulated visible lightwave communication (VLC) system, successfully detecting a PN9 PRBS sequence during testing.

This paper reports a high-performance, broadband flexible photodetector (PD) based on a novel covalant organic polymeric framework material, TPATZTPA. One PD on Si-substrate and another PD on ITO-coated PET-based flexible substrate were fabricated. Both PDs exhibited a similar type of photodetection capability ranging between 350 to 950 nm. In the presence of a broadband white light source, the flexible PD exhibited a peak photo-to-dark current ratio of $18.23 \times 10^{3}$ with a bias of +2 V. Experimental results indicate that the fabricated flexible PD offers a peak responsivity, external quantum efficiency, and specific detectivity of 5.69 A/W at 570 nm, 13.06% at 565 nm, and $1.27 \times 10^{11}$ Jones at 570 nm, respectively. The transient study reveals that the fabricated TPATZTPA-based flexible PD offers a rise and fall time of 0.29 s and 0.28 s, respectively. A simple 50 cm long visible lightwave communication (VLC) system utilizing the fabricated flexible PD exhibited its efficacy by successfully demodulating intensity-modulated PN9 PRBS sequence.

In this letter, a solution combustion synthesized (SCS) CeO2 -based high-performance wideband photodetector (PD) is reported. The SCS method was categorically chosen to narrow the bandgap of synthesized CeO2 via nitrogen or carbon doping and employ the higher level of oxygen vacancies in photodetection. The PD's structure is composed of p-Si/Al/CeO2 /Ag layers, where T1 and T2 are Al and Ag -based electrodes, respectively. The fabricated PD exhibits excellent photodetection capability between 350 nm to 850 nm with a peak responsivity of 12.42 A.W−1 at 411 nm. The highest measured value of external quantum efficiency (EQE) and specific detectivity ( $D^{*}$ ) of the PD are 24.65% at 401 nm and $3.57 \times 10^{10}$ Jones at 501 nm, respectively. The fabricated PD's rise and fall times are measured to be approximately 27 ms and 16 ms, respectively. An experimental application of the proposed PD through a simple visible lightwave communication (VLC) system is also shown.

In this letter, we report a hydrothermally synthesized MoSSe-based wideband photodetector (PD) offering excellent responsivity with sub-second response time. The overall device structure is MXene/MoSSe/Ag with Si as the substrate. The cathode and anode contact of the PD is fabricated with MXene (Ti ₃ C ₂ Tx) and Ag, respectively. The Ti ₃ C ₂ Tx and MoSSe layers are deposited using the spin-coating method, while the Ag electrode is deposited using the thermal evaporation technique. The fabricated PD exhibits excellent photodetection capability between 350 nm to 950 nm with a peak responsivity of 8.89 A.W ⁻¹ at 460 nm. The measured value of external quantum efficiency (EQE), and detectivity ( $D^{*}$ ) of the PD at 420 nm at 24.96% and $9.07 \times 10^{9}$ Jones, respectively. Also, the linearity measurement indicates the efficacy of the PD up to 343 K. In terms of transient performance, the measured rise and fall time of the PD are approximately 0.12 sec and 0.13 sec, respectively.