Ultra high detectivity single carrier multiplication InAs avalanche photodiodes for IR optical detection
Lead Research Organisation:
University of Sheffield
Department Name: Electronic and Electrical Engineering
Abstract
The ability to detect very low light level in the infrared (IR) wavelengths, down to a single photon has numerous applications ranging from enabling highly secured communication that relies on detection of a single photon, measurement of very weak fluorescence in biomolecule identification to high resolution 3 dimensional imaging based on laser ranging. Conventional semiconductor photodiodes do not have the sensitivity required for these photon-starved applications. Therefore it is necessary to use photodiodes designed with internal amplification or gain, called avalanche photodiodes (APDs), to convert the signal from a few photons to a large current that can be detected by an external electronics. In most semiconductors this amplification process also introduces excess noise. However Silicon APDs were able to produce high gain with low excess noise and therefore have been used in many applications to provide detection down to a single photon in the visible wavelengths. This is because, in Silicon the gain is provided predominantly by the electron multiplication process which reduces the excess noise. Unfortunately no commercial IR APD with performance similar to, or better than, Silicon is available despite various proposals to achieve Silicon-like APDs over the last 20 years. This exciting proposal will address this void by developing a new class of APDs based on InAs, a semiconductor with unique band structure features, to achieve high gain with negligible excess noise that is lower than that of Silicon. This proposal aims to provide IR APDs with extremely high performance, capable of detecting a single photon in the wavelength range of 1100 nm to 3000 nm. For instance they can provide low cost high performance large format imaging arrays for IR applications such as LIDAR, a technique that can provide excellent images and range measurements, non-invasive blood glucose sensing, atmospheric CO2 concentration monitoring as well as eye-safe free space optical communication. We therefore expect our APDs to generate new applications and provide highly competitive IR APDs. Based on the understanding of the InAs bandstructure, our APDs will be designed such that only electron will undergo impact ionisation to produce high avalanche gain with negligible excess noise. In addition to excellent gain, our devices can be operated at low voltage, making them compatible with off-the-shelf readout circuits. This could pave the way to a highly sensitive and affordable IR camera. To enhance the exploitation and the gain characteristics we will grow a novel InAsSb APDs on GaAs substrate which is significantly larger and cheaper than InAs substrate. This, if successful, will enable integration with commercial GaAs electronics. To propel our InAs APDs towards exploitation in the applications mentioned above we will;I) Optimise the crystal growth method to achieve high quality InAs materials with low level of impurities.II) Develop fabrication and surface passivation techniques to yield devices with low leakage current, leading to higher sensitivity.III) Pioneer techniques to implant ion species and to perform dopant diffusion to control the electric field in the InAs devices leading to high reliability.IV) Control growth conditions such as temperature and atomic pressure to achieve low crystal defect formation during the growth of InAsSb APDs on GaAs.This exciting project will be carried out by a highly skilled research team, comprising UK universities (Sheffield, Heriot-Watt and Surrey), American university (Virginia) and UK companies (Selex-Galileo and Thales Optronics) with years of experience in research and development of sensing applications. Thus, one of the outputs of the project is to provide a leading IR sensor technology to the research communities to facilitate new research and to the industry to maintain a lead in the IR sensor market.
Planned Impact
IR wavelengths of 2000-4000nm have been used to monitor industrial emission including NH3, CO2, CO and CH4 using the differential absorption LIDAR (DIAL) technique. InSb pin diodes cooled to 77K have high detectivity and hence are usually the preferred IR detector. However despite this high detectivity InSb pin diodes can only produce a single electron-hole pair per photon and hence limits the sensitivity of DIAL systems, for instance to a maximum range of 1 km with a sensitivity of 50 ppb when used to detect CH4. Our minimally cooled InAs APDs will provide a significant enhancement to the DIAL sensitivity at the IR wavelengths up to ~3500nm since high gain can be obtained with negligible excess noise factors. A TE-cooled InAs pin diode without gain can provide detectivity similar to that of InSb. Therefore our high gain InAs APDs can be expected to provide orders of magnitude increase in the detectivity, enabling detection at the single photon level. The National Physical Laboratory (NPL) has developed one of the best DIAL systems for industrial volatile organic compound emission. We have initiated preliminary discussion with the NPL to evaluate InAs APDs for incorporation into their DIAL system. It is expected that at the end of the project, high performance InAs APDs could be supplied to NPL for evaluation. A satellite borne DIAL system can provide very accurate measurement of CO2 levels in the atmosphere. CO2 is strongly absorbed at the wavelength of 2000nm. The European Space Agency (ESA) has a strong interest in high performance IR APDs for this application. Our APDs can be developed to meet the detector specifications for future ESA CO2 monitoring programmes. We have engaged with ESA in recent years in this topic and have a clear exploitation route for satellite based research via ESA and ESA contractors, Surrey Satellite Technology Ltd. The performance of conventional long range passive long wave IR imaging systems have limited resolution and are prone to vibration and interference from surroundings. Active imaging systems at shorter IR wavelengths can overcome these limitations. Of special interest is the wavelength of 1550nm because it is relatively eyesafe, has a good atmospheric transmission characteristics and availability of high quality laser sources. Therefore laser gated imaging (LGI) provides an excellent 3-D imaging capability when a focal plane array is used. Selex-Galileo is a leading manufacturer in LGI systems using an array of highly sensitive 1550nm photodiodes and provides a clear exploitation path for detectors developed in this project. To overcome the noise floor of the system, a gain mechanism is required to amplify photocurrent generated by returning photons. Hence our high gain InAs APDs with minimal cooling and operating with low reverse bias will be ideally suited for cost effective laser gated imaging systems. Thales Optronics has a wide range of surveillance and thermal imaging products. InAs APDs can provide low cost high performance detectors for applications such as low-light imaging and spectral imaging. Hence they can be complementary to Thales' existing range of imaging products. Quantum Key Distribution (QKD) has received intense interest as highly secure communication system. However, despite much publicity, current systems are limited by system transmission range (usually 10's km) and key exchange rate (kbits-1) which is caused by detector dark counts, and particularly afterpulsing effects (these are false detections) in the detectors used, typically InGaAs/InP APDs. Although NbN nano-wire superconductors are used in some high-performance QKD demonstrations, such detectors require expensive and bulky cooling system to achieve the operating temperature of a few Kelvin. Therefore InAs devices can provide the much needed high performance detectors for QKD systems.
Publications
Auckloo A
(2014)
A low noise op-amp transimpedance amplifier for LIDAR applications
Butera S
(2016)
Picosecond laser ranging at wavelengths up to 2.4 µm using an InAs avalanche photodiode
in Electronics Letters
Gomes R
(2011)
InAs avalanche photodiodes for X-ray detection
Gomes R
(2011)
InAs avalanche photodiodes for X-ray detection
in Journal of Instrumentation
Ker P
(2011)
Low noise high responsivity InAs electron avalanche photodiodes for infrared sensing
in physica status solidi c
Ker P
(2011)
Temperature Dependence of Leakage Current in InAs Avalanche Photodiodes
in IEEE Journal of Quantum Electronics
Ker PJ
(2012)
Temperature dependence of gain and excess noise in InAs electron avalanche photodiodes.
in Optics express
Lim L
(2019)
Improved Planar InAs Avalanche Photodiodes With Reduced Dark Current and Increased Responsivity
in Journal of Lightwave Technology
Marshall A
(2010)
High gain InAs electron-avalanche photodiodes for optical communication
Marshall A
(2010)
Impact Ionization in InAs Electron Avalanche Photodiodes
in IEEE Transactions on Electron Devices
Marshall A
(2011)
Avalanche Multiplication and Excess Noise in InAs Electron Avalanche Photodiodes at 77 K
in IEEE Journal of Quantum Electronics
Marshall AR
(2011)
High speed InAs electron avalanche photodiodes overcome the conventional gain-bandwidth product limit.
in Optics express
Meng X
(2015)
InAs avalanche photodiodes as X-ray detectors
in Journal of Instrumentation
Sandall I
(2014)
Temperature dependence of impact ionization in InAs: erratum
in Optics Express
Sandall I
(2012)
Planar InAs photodiodes fabricated using He ion implantation
Sandall I
(2014)
Demonstration of InAsBi photoresponse beyond 3.5 µ m
in Applied Physics Letters
Sandall I
(2012)
1300 nm Wavelength InAs Quantum Dot Photodetector Grown on Silicon
in Optics Express
Sandall I
(2012)
Planar InAs photodiodes fabricated using He ion implantation.
in Optics express
Sandall I
(2012)
InAs quantum dot photodetector operating at 1.3 µm grown on Silicon
Sandall I
(2013)
Evaluation of InAs quantum dots on Si as optical modulator
in Semiconductor Science and Technology
Sandall I
(2014)
InAsBi photodiode operating in the MWIR
Sandall I
(2014)
InAs APD with solid state photomultiplier characteristics
Description | We have developed a new detector technology using InAs semiconductor. The detector can detect very weak infrared signal since it can provide internal amplification without introducing noise. We have shown that InAs can provide high internal gain without incurring high amplification noise. Detectors made from InAs can also provide high amplification at high response speed (no bandwidth limitation due to the amplification process).We are now able to detect low light levels down to 10-30 photons. |
Exploitation Route | The Technology Readiness Level needs to be increased to improve the reliability so that it can be manufactured for full exploitation. We have significantly raised the TRL under a follow-on funding from European Space Agency to evaluate the InAs detector for Carbon Dioxide Monitoring. InAs detectors have also be evaluated for radiation thermometry with results generated some interest from LAND Ametek. |
Sectors | Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Manufacturing, including Industrial Biotechology |
Description | The results are subject of invited talks in a number international conferences. |
First Year Of Impact | 2011 |
Sector | Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Manufacturing, including Industrial Biotechology |
Impact Types | Economic |
Description | CDE Phase 2: Imaging Through Obscurant |
Amount | £100,000 (GBP) |
Organisation | Defence Science & Technology Laboratory (DSTL) |
Sector | Public |
Country | United Kingdom |
Start | 09/2017 |
End | 08/2018 |
Description | InAs APD development for NIR and SWIR applications |
Amount | £400,000 (GBP) |
Funding ID | 4000107110 |
Organisation | European Space Agency |
Sector | Public |
Country | France |
Start | 01/2013 |
End | 01/2015 |
Description | InAsNSb Dilute Nitride Materials for Mid-infrared Devices & Applications. |
Amount | £226,162 (GBP) |
Funding ID | EP/J015814/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2012 |
End | 08/2015 |
Description | Low-light level infrared LIDAR using electron multiplying semiconductor detectors |
Amount | £60,000 (GBP) |
Funding ID | P12016--03--004 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2017 |
End | 03/2018 |
Description | Novel lateral cascaded InAs avalanche photodiodes for infrared sensing: Towards a true solid state photomultiplier |
Amount | £168,900 (GBP) |
Funding ID | DSTLX1000064084 |
Organisation | Defence Science & Technology Laboratory (DSTL) |
Sector | Public |
Country | United Kingdom |
Start | 08/2012 |
End | 02/2016 |
Description | Ratio detectors incorporating on-chip temperature monitoring |
Amount | £99,378 (GBP) |
Funding ID | R/142644 |
Organisation | University of Sheffield |
Sector | Academic/University |
Country | United Kingdom |
Start | 01/2015 |
End | 09/2015 |
Description | Research and Development into Imaging through obscurants using single photon and few photon approaches in short wave infrared |
Amount | £79,030 (GBP) |
Funding ID | CDE100963 |
Organisation | Defence Science & Technology Laboratory (DSTL) |
Sector | Public |
Country | United Kingdom |
Start | 11/2016 |
End | 04/2017 |
Description | Single Photons - Expanding the Spectrum (SPEXS) |
Amount | £5,265,567 (GBP) |
Funding ID | EP/S026428/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2019 |
End | 09/2024 |
Description | Project Partner Selex Galileo |
Organisation | Selex ES |
Department | SELEX Galileo Ltd |
Country | United Kingdom |
Sector | Private |
PI Contribution | Sheffield has developed InAs APD technology that has the potential to be developed into complementary products from Selex. |
Collaborator Contribution | Selex has provide advise and guidance in development of array detectors. |
Impact | No notable output at this stage. |
Start Year | 2010 |
Description | Project partner University of Virginia |
Organisation | University of Virginia (UVa) |
Country | United States |
Sector | Academic/University |
PI Contribution | We have transferred the device fabrication process to Virginia. |
Collaborator Contribution | Provide cross measurements of results and discussion. |
Impact | Virginia University has published a number of papers in InAs APDs. |
Start Year | 2010 |
Description | Development of very low noise high gain InAs avalanche photodiodes, International Compound Semiconductor Conference, Aug. 2012, Santa Barbara, USA. |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Participants in your research and patient groups |
Results and Impact | This invited talk highlighted the unique properties of InAs avalanche photodiodes. As a results the research community is now aware of an extremely low noise avalanche photodiodes. No notable impact immediately after the talk. |
Year(s) Of Engagement Activity | 2012 |
Description | IEEE Photonics Conference, IPC 2015 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Talk title was Planar InAs avalanche photodiodes. The procedures to fabricate InAs Avalanche Photodiodes using Be ion implantation was reported for the first time. White, B. S., Sandall, I. C., & Tan, C. H. (2015). Planar InAs avalanche photodiodes. In 2015 IEEE Photonics Conference, IPC 2015 (pp. 454-455). doi:10.1109/IPCon.2015.7323571 |
Year(s) Of Engagement Activity | 2015 |
Description | InAs APD with solid state photomultiplier characteristics, IEEE Photonic Conference, Oct. 2014, San Diego, USA |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Participants in your research and patient groups |
Results and Impact | The invited talk highlighted progress in new technology for researchers. I was approached by a few researchers who expressed interest in collaboration. Collaborative work has been discussed with a company called Laser Components. |
Year(s) Of Engagement Activity | 2014 |
Description | InAs Electron-Avalanche Photodiodes: From leaky diodes to extremely low noise avalanche photodiodes, IEEE Photonic Conference, Oct. 2011, Washington, USA |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Participants in your research and patient groups |
Results and Impact | This is an invited talk. Some discussion of the commercial potential took place. Talk has stimulated research in the topic in USA. |
Year(s) Of Engagement Activity | 2011 |
Description | Invited presentation at SPIE Defense and Commercial Sensing, Anaheim, California, USA, 9-13 April 2017. |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Presented progress made in InAs avalanche photodiodes. Results showing that InAs can now detect very few photons, lead to potential interest in using InAs for ranging applications and imaging at various infrared wavelengths. Discussion includes imaging through fog, and detecting distanced objects. Several research groups indicated interested to collaborate. |
Year(s) Of Engagement Activity | 2017 |
Description | Invited talk at The 36th II-VI Workshop, Chicago, USA |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Between 100-200 researchers from various universities and engineers from industry attended this invited talk. My work was based on InAs which is considered a competing technology to the II-VI technology. The recognition and the opportunity to present the progress made are good indication of potential impact of InAs based avalanche photodiodes. |
Year(s) Of Engagement Activity | 2017 |
Description | Low photon detection with InAs low noise APDs, MIOMD, Oct. 2014, Montpellier, France. |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Participants in your research and patient groups |
Results and Impact | This is an invited presentation at the conference MIOMD at Montpellier France in Oct. 2014. It is attended by researchers in the mid infrared devices. Progress made from the InAs APD work was presented. It generated interested from other groups in the world. I was approached by a some researchers who expressed interest in forming collaboration. Started a collaboration with a group based at Montopellier. |
Year(s) Of Engagement Activity | 2014 |
Description | MIOMD Beijing 2016 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Invited talk. Title: Towards photon counting beyond 2?m using InAs e-APDs |
Year(s) Of Engagement Activity | 2016 |
Description | SPIE security Edinburgh 2016 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Invited talk in SPIE Security and Defense In Proceedings of SPIE Vol. 9988. Society of Photo-optical Instrumentation Engineers. doi:10.1117/12.2243146 |
Year(s) Of Engagement Activity | 2016 |