Infrared Photon Detectors Research Articles

Broadband polarization-independent infrared photon upconversion within nanophotonic lithium niobate waveguides by higher-order-mode engineering.

A broadband polarization-independent infrared photon upconversion scheme based on nanophotonic waveguides on the lithium niobate on insulator (LNOI) platform is proposed. With the introduction of higher-order-mode dispersion engineering, polarization-independent and broadband photon upconversion with a maximum bandwidth of nearly 46 nm is achieved in this device. The proposed broadband polarization-independent photon upconversion structure shows great potential applications in on-chip infrared photon detection and nonlinear photonics.

Advancements in Uncooled Bolometer Technology: Shortwave Infrared Detection via CuFeSe2 Nanocrystal Colloidal Thin Films

Microbolometers have emerged as a cost‐effective alternative to cooled infrared photon detectors, albeit with certain trade‐offs in terms of responsivity (), detectivity (), and response time (). The research in this field is driven by the potential applications in night vision devices, military surveillance, and autonomous vehicles, leading to a growing interest in exploring new materials to bridge the performance gap between cooled photon detectors and uncooled bolometers. This study focuses on the optoelectronic and bolometric characteristics of nanocrystals (NCs) in a colloidal solution. These NCs exhibit a significant change in resistivity (ρ) when subjected to temperature variations ranging from 170 to 400 K. Specifically, the temperature coefficient of resistance (TCR), α, is 1.9% per Kelvin for a room temperature resistivity of 505 Ω cm. Furthermore, the responsivity of NCs is reported to be 0.101 A W−1, and the Hall mobility of the colloidal solution is determined as . Finally, a comprehensive comparison is conducted between the performance metrics of established bolometer materials, such as VOx and a‐Si, and those of colloidal NCs. Based on the results, colloidal NCs are a promising option for future bolometer technology.

Broadband-Spectral-Responsivity of black silicon photodetector with high gain and sub-bandgap sensitivity by titanium hyperdoping

Silicon, as one of the most essential semiconducting materials, is widely applied in various photodetection applications due to its high portability, convenient preparation, and compatibility with conventional complementary metal–oxide–semiconductor technology. Nowadays, black silicon, prepared by enforcing ultrafast laser micro-structuring and hyperdoping techniques, has received considerable attention for developing next-generation silicon photonics and silicon optoelectronics devices. In this work, high-comprehensive-property black silicon photodetectors with broadband spectral responsivity and high gain were achieved by femtosecond laser irradiation and titanium hyperdoping. The proposed device can respond to the incident light from 400 nm to at least 1550 nm, demonstrating a high responsivity of 40.59 A/W for 950 nm under the application of −5 V bias, and the corresponding detectivity can reach 3.61 × 1012 cm·Hz1/2W−1. Moreover, the fabricated photodetector exhibits a stable sub-bandgap photocurrent at 1550 nm, with an average responsivity of 3.42 mA/W by applying a −5 V bias. These improvements were achieved by the hyperdoping of titanium in silicon, which shows deep impurity levels, low electroactivity, and increased effective carrier lifetimes, as well as the formation of shallow n-i heterojunction and trapping centers induced by the femtosecond laser irradiation. Our work provides significant insights into the applications of black silicon in various optical-related fields, including weak and infrared photon detection, silicon photonic chips, remote sensing, and large-scale optoelectronic integration.

Quantum Fourier-transform infrared spectroscopy in the fingerprint region.

Infrared quantum absorption spectroscopy is one of the quantum sensing techniques, by which the infrared optical properties of a sample can be estimated through visible or near infrared photon detection without need for infrared optical source or detector, which has been an obstacle for higher sensitivity and spectrometer miniaturization. However, experimental demonstrations have been limited to wavelengths shorter than 5 µm or in the terahertz region, and have not been realized in the so-called fingerprint region of 1500-500 cm-1 (6.6 to 20 µm), which is commonly used to identify chemical compounds or molecules. Here we report the experimental demonstration of quantum Fourier-transform infrared (QFTIR) spectroscopy in the fingerprint region, by which both absorption and phase spectra (complex spectra) can be obtained from Fourier transformed quantum interferograms obtained with a single pixel visible-light detector. As demonstrations, we obtained the transmittance spectrum of a silicon wafer at around 10 µm (1000 cm-1) and complex transmittance spectrum of a synthetic fluoropolymer sheet, polytetrafluoroethylene, in the wavelength range of 8 to 10.5 µm (1250 to 950 cm-1), where absorption due to stretching modes of C-F bonds is clearly observed. These results open the way for new forms of spectroscopic devices based on quantum technologies.

Nonlinear Infrared Photodetection Based on Strong Nondegenerate Two‐Photon Absorption of Perovskite Single Crystal

AbstractHalide perovskites have been recently shown to exhibit strong nonlinear optical properties such as two‐photon absorption, second harmonic generation, etc. In this work, the nondegenerate two‐photon absorption, i.e., when the energies of two photons absorbed are not the same, of methylammonium lead bromide single crystal is studied. It is found that the nondegenerate two‐photon absorption is much stronger than the degenerate two‐photon absorption. For the photon pair ℏω1 = 2.96 eV, ℏω2 = 0.73 eV, the nondegenerate two‐photon absorption coefficient reaches 51.3 cm GW−1, which is around 6 times that of degenerate two‐photon absorption. Taking advantage of the strong nondegenerate two‐photon absorption, a nonlinear infrared pulse photodetector based on the combination of a methylammonium lead bromide single crystal and a silicon photodiode is developed. The infrared femtosecond laser pulses at 1700 nm can be well measured with a resolution on the order of 1 nJ and responsivity of 68 V W−1. These findings provide novel insight for the understanding of nondegenerate nonlinear optical properties in halide perovskites and may open a new avenue for the development of high‐sensitivity infrared photon detection.

Proton irradiation effects on InGaAs/InAsSb mid-wave barrier infrared detectors

Semiconductor-based mid-wave infrared photon detectors that functionalize space-based imaging systems are susceptible to both cumulative ionization and displacement damage, especially due to proton irradiation. Here, the dark current density and quantum efficiency of a mid-wave infrared detector utilizing a strain-balanced InGaAs/InAsSb superlattice active region are examined as a function of a 63 MeV proton radiation dose. Proton-irradiation is performed in an incremental stepwise dose up to a total ionizing dose of 100 krad(Si) or an equivalent proton fluence of 6.1 × 1011 protons/cm2. All characterization work is conducted with the detectors held at an operating temperature of 130 K throughout the experiment to limit thermal annealing effects. Prior to irradiation, the quantum efficiency of the top-side illuminated device without anti-reflection coating is 59.5%. The quantum efficiency is largely independent of temperature below 150 K, indicative of an electron minority carrier. As irradiation progressed the typical linear increase in inverse quantum efficiency with increasing proton fluence was observed, which led to a quantum efficiency damage factor of 1.12 × 1013 e cm2/ph. This value is shown to be an order of magnitude lower than typically observed in III-V nBn devices and is likely due to the higher mobility of minority electrons in the active region of this device. A full analysis of the characterization results suggests that displacement damage creates a significant population of donor states that modify the doping profile, in addition to Shockley–Read–Hall recombination centers that generally form as a result of proton irradiation.

Determination of the contributions of degenerate and non-degenerate two-photon absorption response in silicon avalanche photodiode for infrared photon detection

The study of non-linear interactions in semiconductor photo-electronic devices to achieve effective and fast photon identification is an ongoing and important task. We investigated the specific contribution of degenerate and non-degenerate two-photon absorption (D-TPA and ND-TPA) response in silicon avalanche photodiode (Si-APD) for infrared photon detection at room temperature. We experimentally demonstrated that when the two laser pulses overlapped, the average D-TPA quantum detection efficiencies at 1800 nm, and that at 1550 nm were measured as 3.3 × 10−16 counts•pulse/photon2, 4.3 × 10−15 counts•pulse/photon2, respectively. And the ND-TPA quantum detection efficiency of 1800 nm and 1550 nm was measured to be 7.9 × 10−16 counts•pulse/photon2. This study provides a solution for the practical infrared photon detection devices based on TPA effect in Si-APDs.

Characterizing TES power noise for future single optical-phonon and infrared-photon detectors

In this letter, we present the performance of a 100 μm × 400 μm × 40 nm W Transition-Edge Sensor with a critical temperature of 40 mK. This device has a noise equivalent power of 1.5×10-18 W/Hz, in a bandwidth of 2.6 kHz, indicating a resolution for Dirac delta energy depositions of 40 ± 5 meV (rms). The performance demonstrated by this device is a critical step toward developing a O(100) meV threshold athermal phonon detector for low-mass dark matter searches.

Sensitive Infrared Photon Counting Detection by Nondegenerate Two-Photon Absorption in Si APD

We report on the sensitive detection of photons at broadband infrared wavelengths based on the nondegenerate two-photon absorption in the Si avalanche photodiodes. The detected 1700~1850 nm infrared photon energy is lower than Si band gap and the energy difference is complemented by a high intensity pump laser field at 1550 nm. It is thus possible to capitalize on the low noise property of large band gap materials for detecting low energy photons. And the linear intensity response of the detector to the incident infrared photons was observed when the power of pump laser was about $12.42\mu $ W, indicating the dominance of nondegenerate two-photon absorption in the infrared photon detection. An enhancement factor of 20 was observed for the incident signal photon numbers of $\sim 0.14\times 10^{\mathbf {6}}$ photons per pulse. We offer an alternative to sensitive detection of infrared light. This may also provide new ideas for broadband infrared photon detection in different applications such as optical comb laser ranging, infrared bio-image and so forth.

Sensing Infrared Photons at Room Temperature: From Bulk Materials to Atomic Layers.

Room-temperature operating means a profound reduction of volume, power consumption, and cost for infrared (IR) photodetectors, which promise a wide range of applications in both military and civilian areas, including individual soldier equipment, automatic driving, etc. Inspired by this fact, since the beginning of 1990s, great efforts have been made in the development of uncooled thermal detectors. During the last two decades, similar efforts have been devoted using IR photon detectors, especially based on photovoltaic effects. Herein, the proven technologies, which have been commercialized with a large format, like InGaAs/InP pin diodes, InAsSb barrier detectors, and high-operating-temperature HgCdTe devices, are reviewed. The newly developed technology is emphasized, which has shown unique superiority in detecting mid-wavelength and long-wavelength IR signals, such as quantum cascade photodetectors. Finally, brand-new concept devices based on 2D materials are introduced, which are demonstrated to provide additional degrees of freedom in designing and fabricating room-temperature IR devices, for example, the construction of multi-heterojunctions without introducing lattice strain, the convenient integration of optical waveguides and electronic gratings. All information provided here aims to supply a full view of the progress and challenges of room-temperature IR detectors.

Ultrasensitive Mid-wavelength Infrared Photodetection Based on a Single InAs Nanowire.

One-dimensional InAs nanowire (NW)-based photodetectors have been widely studied due to their potential application in mid-wavelength infrared (MWIR) photon detection. However, the limited performance and complicated photoresponse mechanism of InAs NW-based photodetectors have held back their true potential for real application. In this study, we developed ferroelectric polymer P(VDF-TrFE)-coated InAs NW-based photodetectors and demonstrated that the electrostatic field caused by polarized ferroelectric materials modifies the surface electron-hole distribution as well as the band structure of InAs NWs, resulting in ultrasensitive photoresponse and a wide photodetection spectral range. Our single InAs NW photodetectors exhibit a high responsivity ( R) of 1.6 × 104 A W-1 as well as a corresponding detectivity ( D*) of 1.4 × 1012 cm·Hz1/2 W-1 at a light wavelength of 3.5 μm without an applied gate voltage, ∼3-4 orders higher than the maximum value of photoresponsivity reported or commercially used MWIR photodetectors. Moreover, our device shows below band gap photoresponse for 4.3 μm MWIR light with R of 9.6 × 102 A W-1 as well as a corresponding D* of ∼8.5 × 1010 cm·Hz1/2 W-1 at 77 K. Our study shows that this approach is promising for fabrication of high-performance NW-based photodetectors for MWIR photon detection.

Anomalous light-to-electricity conversion of low dimensional semiconductor in p-n junction and interband transition quantum well infrared detector

Recently, high localized carrier extraction efficiency and enhanced absorption coefficient were observed in low-dimensional semiconductor within a p-n junction. In this work, we report the discovery and verification of the phenomenon, and the performance of the first photon detector based on the interband transition of strained InGaAs/GaAs quantum wells (QWs). By introducing the resonant excitation photoluminescence, the same phenomena are observed in several different material systems. More than 95% of the photoexcited carriers escape from InGaN/GaN QWs, and 87.3% in InGaAs/GaAs QWs and 88% in InAs/GaAs quantum dots are observed. The external quantum efficiency of the device is measured to be 31% by using an absorption layer with only 100 nm effective thickness in the case without an anti-reflection layer. Using such a high value of quantum efficiency, an absorption coefficient of 3.7104 cm-1 is calculated, which is obviously larger than previously reported values. The results here demonstrate the possibility of fabricating high-performance and low-cost infrared photon detectors.

被动式红外感应自动水龙头的设计

本文介绍一种被动红外感应式水龙头，利用人体产生的红外辐射作为信号源，选用红外光子型探测器掺杂锗来探测，可以高效响应人体辐射的峰值波长，并且响应快，受环境温度影响小。在详细分析人体辐射特性的基础上，选择合适的红外探测器和相应的信号处理电路，设计了被动式红外感应自动水龙头系统，用指示灯代替水龙头，并验证了设计方案的正确性。 The article introduces a kind of passive infrared induction faucet, that is infrared radiation generated by the human body as a signal source, chooses the infrared photon detector doping germanium to detect, which can efficient response to the peak wavelength of radiation human body, and response rapidly, free from interference environmental temperature. On the basis of detailed analysis of the human body radiation characteristics and selecting the appropriate infrared detector, the design of passive infrared induction automatic faucet was built, with the corresponding signal processing circuit, using indicator light instead of faucet, validated the correctness of design scheme.

Influence of Hydrogenation on Electrical Conduction in HgCdTe Thin Films on Silicon

HgCdTe is the standard state-of-the-art infrared detector material for space applications. HgCdTe-based infrared photon detector performance can be hindered due to the presence of bulk crystal defects and dangling bonds at surfaces or interfaces. Passivation of such bulk defects and surfaces can potentially improve detector performance by saturating dangling bonds in dislocation cores and at surfaces. Indeed, results showing improvement of HgCdTe current–voltage characteristics after hydrogenation have been reported. Here we use multiple-carrier fitting of Hall-effect data, acquired under variable magnetic field strengths and sample temperatures, to investigate the physical influence of hydrogenation, as a passivation procedure, on HgCdTe crystalline thin films on Si(211) substrates. We find: (1) evidence of multiple active electrical carrier species in all samples, (2) evidence of surface electrical conduction before and after hydrogenation, and (3) changes in carrier concentration and mobility induced by hydrogenation.

Design of Phosphorus-Containing MWIR Type-II Superlattices for Infrared Photon Detectors

Type-II strained layer superlattices (SLSs) offer a broad range of design degrees of freedom to help optimize their properties as absorber layers of infrared photon detectors. We theoretically examine a new class of mid-wavelength infrared (2-5 μm bandpass) Type-II structures with two-layer InGaSb/InPSb and four-layer InAs/GaSb/InAs/InPSb SLS periods. Phosphorous-containing SLSs are a promising approach to improving infrared photon detector performance due to providing a new set of material properties, including favorable valence band offsets. P-based SLSs of four-layer type InAs/GaSb/InAs/InPSb were found to be among the best 5-μm gap SLSs that we have modeled. Among the studied designs, the lowest dark current in an ideal structure is predicted for a four-layer 23.6 A InAs/20 A GaSb/23.6 Å InAs/60 Å InP 0.62Sb0.38 SLS. Its predicted ideal dark current is about 35 times lower than an n-type HgCdTe-based photodiode absorber and six times lower than a p-type HgCdTe one for the same bandgap, temperature, and dopant concentration. We also discuss a defect mitigation strategy that involves positioning the SLS gap in an energy range that avoids defect levels and show how this applies to the aforementioned P-containing SLS.

Sine gating detector with simple filtering for low-noise infra-red single photon detection at room temperature

We present and analyze a gated single photon avalanche detector using a sine gating scheme with a simple but effective low-pass filtering technique for fast low-noise single photon detection at telecom wavelength. The detector is characterized by 130 ps short gates applied with a frequency of 1.25 GHz, yields only 70 ps timing jitter and noise probabilities as low as 7·10−7 per gate at 10% detection efficiency. We show that the detector is suitable for high rate quantum key distribution (QKD) and even at room temperature it could allow for QKD over distances larger than 25 km.

MBE HgCdTe for HDVIP Devices: Horizontal Integration in the US HgCdTe FPA Industry

Molecular beam epitaxy (MBE) growth of HgCdTe offers the possibility of fabricating multilayer device structures with an almost unlimited choice of infrared sensor designs for focal-plane array (FPA) fabrication. HgCdTe offers two major advantages that explain its dominance in the infrared photon detector marketplace. The thermal generation rate per unit volume of the material is lower and the quantum efficiency for photon absorption in the infrared is higher in HgCdTe than in any competing material—it yields devices with quantum efficiencies as high as 0.99. Recently, EPIR Technologies and DRS Infrared Technologies agreed to collaborate and examine: (i) the feasibility of employing MBE HgCdTe in the fabrication of high-density vertically interconnected photodiodes (HDVIPs), which are usually fabricated with liquid-phase epitaxy material, and (ii) the potential benefits of horizontal integration, with EPIR supplying the MBE materials to DRS for device and array fabrication. The team designed and developed passivation–absorber–passivation structures that are heavily used by DRS. This paper provides an overview of the characteristics of HDVIP devices and arrays fabricated from MBE HgCdTe and the anticipated advantages of horizontal integration in the industry. Material growth, device fabrication, and test results are presented.

Some Failure Mechanisms in Charge-Sensitive Infrared Phototransistors

For an infrared photon detector, such as charge-sensitive infrared phototransistors (CSIPs), we propose and use a capacitive charging method to study some failure mechanisms that disable the photon response of CSIPs. Two failure mechanisms are highlighted, namely interquantum well (QW) leakage and low tunneling probability for intersubband-transition-excited electrons. A correlation between the Al content in the inter-QW AlGaAs barrier and the failure mechanism type are discussed. On the other hand, the previously unexplained puzzle that the success of photon response is only weakly dependent on the QW electron mobility that is attributed to an imperfect inter-QW barrier.

Full-band Monte Carlo simulation of high-energy carrier transport in single photon avalanche diodes with multiplication layers made of InP, InAlAs, and GaAs

We investigate the high-energy charge dynamics of electrons and holes in the multiplication process of single photon avalanche diodes. The technologically important multiplication layer materials InP and In0.52Al0.48As, used in near infrared photon detectors, are analyzed and compared with GaAs. We use the full-band Monte Carlo technique to solve the Boltzmann transport equation which improves the state-of-the-art treatment of high-field carrier transport in the multiplication process. As a result of the computationally efficient treatment of the scattering rates and the parallel central processing unit power of modern computer clusters, the full-band Monte Carlo calculation of the breakdown characteristics has become feasible. The breakdown probability features a steeper rise versus the reverse bias for smaller multiplication layer widths for InP, In0.52Al0.48As, and GaAs. Both the time to avalanche breakdown and jitter decrease with shrinking size of the multiplication region for the three examined III–V semiconductors.

Interferometric autocorrelation in the ultraviolet utilizing spontaneous parametric down-conversion inside an enhancement cavity

Autocorrelation is a common method to estimate the duration of ultrashort laser pulses. In the ultraviolet (UV) regime it is challenging to employ the process of second-harmonic generation, most prominently due to absorption in nonlinear crystals at very short wavelengths. Here we show how to utilize spontaneous parametric down-conversion (SPDC) to generate an autocorrelation signal in the infrared (IR) for UV pulses. Our method utilizes the nth-order emission of the SPDC process, which occurs for low pumping powers proportional to the nth power of the UV intensity. Thus, counting 2n down-converted photons directly yields the nth-order autocorrelation. The method, now with detection of near-IR photons, is applied to the first direct measurement of ultrashort UV pulses circulating inside a UV enhancement cavity.