Application of the Photoelectric Effect in Infrared Remote Sensing

Technology

Haotian Song

College of Physics, Jilin University, Changchun, Jilin, 130000, China

Keywords: Photoelectric Effect, Infrared Remote Sensing Technology, Infrared Detector, Thermal Imaging Technology,

Spectral Analysis.

Abstract: Infrared remote sensing technology plays a vital role in military, geological, agricultural, and medical fields

due to its unique advantages. Centered on the theory of the photoelectric effect, this technology converts

invisible infrared radiation into electrical signals to enable target detection and data analysis. This review

comprehensively examines the applications of the photoelectric effect in infrared remote sensing. It begins

with a retrospective analysis of the theoretical evolution of the photoelectric effect, including the fundamental

principles of external and internal photoelectric effects, as well as the components and operational

mechanisms of infrared remote sensing systems. Subsequently, it focuses on the specific applications of the

photoelectric effect in infrared detectors, thermal imaging technology, and spectral analysis, evaluating the

performance characteristics and practical scenarios of devices such as HgCdTe detectors, InSb detectors, and

quantum well infrared detectors. Finally, by integrating emerging trends in nanomaterials, quantum dot

technology, and artificial intelligence (AI), the review envisions future prospects for photoelectric effect

applications in infrared remote sensing, including the utilization of novel materials like graphene,

optimization of quantum dot infrared detectors, and breakthroughs in intelligent data processing. This work

aims to provide readers with a holistic perspective on the integration of photoelectric effects with infrared

remote sensing while highlighting its innovative potential across multidisciplinary domains.

1 INTRODUCTION

Infrared remote sensing technology, as a crucial

means of acquiring information in modern times, is

widely used in military, geological, agricultural,

medical, and other related fields, playing a vital role.

The core of this technology lies in converting

imperceptible infrared radiation signals into

detectable electrical signals through the photoelectric

effect and processing the data.

The photoelectric effect describes light-induced

electron emission from materials. Discovered by

Hertz in 1887, it underpins infrared (IR) detector

development. As the core of IR remote sensing

systems, detector performance, governed by this

effect, directly impacts system capabilities. The

effect's properties dictate critical detector parameters,

including response speed, resolution, sensitivity, and

operational wavelength range. This fundamental

mechanism enables photoelectric conversion in IR

https://orcid.org/0009-0008-7647-3169

detection, driving advancements in sensing

technology.

This study examines the photoelectric effect's

implementation in infrared remote sensing,

evaluating its strengths and shortcomings while

assessing the technology's present state and

evolutionary trajectory.

2 THEORY OF

PHOTOELECTRIC EFFECT

AND INFRARED REMOTE

SENSING TECHNOLOGY

2.1 Development History of

Photoelectric Effect Theory

In 1887, Hertz discovered electromagnetic waves and

determined their speed. In 1889, Hallwachs found

286

Song, H.

Application of the Photoelectric Effect in Infrared Remote Sensing Technology.

DOI: 10.5220/0013824300004708

Paper published under CC license (CC BY-NC-ND 4.0)

In Proceedings of the 2nd International Conference on Innovations in Applied Mathematics, Physics, and Astronomy (IAMPA 2025), pages 286-290

ISBN: 978-989-758-774-0

that a zinc plate produced an electric charge under

ultraviolet irradiation. In 1900, Lenard

experimentally proved that metals emit electrons

under ultraviolet irradiation. In 1905, Einstein

proposed the quantum hypothesis to explain the

photoelectric effect. In 1916, Millikan verified the

quantum hypothesis and measured Planck's constant.

Einstein further provided a quantum explanation

for the photoelectric effect: "Energy during the

propagation of a ray of light is not continuously

distributed over steadily increasing spaces, but it

consists of a finite number of energy quanta localized

at points in space, moving without dividing and

capable of being absorbed or generated only as

entities."

Einstein's photoelectric equation:

𝐸=ℎ𝜈=𝜙+𝐾



(1)

E = hν represents the energy of a single photon,

where: E is the energy of the photon;h is Planck's

constant;ν is the frequency of the incident light.

Einstein also won the Nobel Prize in Physics for

his work on the photoelectric effect.

2.2 External and Internal Photoelectric

Effects

The photoelectric effect is divided into external and

internal photoelectric effects. The external

photoelectric effect refers to photons exciting

electrons from the material surface into a vacuum,

forming photoelectrons. The internal photoelectric

effect refers to photons exciting electrons from the

valence band to the conduction band, generating

electron-hole pairs. The "external" in the external

photoelectric effect indicates that the bound electron

is excited by a photon of a certain frequency and then

jumps out of the metal to become a photon, which is

a description of the final position of an excited

electron. The more specific manifestation of the

internal photoelectric effect is that when light shines

on an object, there is a change in the conductivity of

the object, or a change in the electromotive force.

2.3 Infrared Remote Sensing

Technology

Infrared radiation is electromagnetic waves with

wavelengths between visible light and microwaves.

All objects with temperatures above absolute zero

emit infrared radiation. Infrared remote sensing

technology utilizes this self-emitted or reflected

infrared radiation to detect and identify targets.

Infrared remote sensing technology mainly consists

of the following components:

Infrared Sensor: Commonly used to detect

infrared radiation and convert it into detectable

electrical signals. Optical System: Includes lenses and

mirrors to focus infrared radiation onto the

sensor.Cooling System: Cools the sensor to low

temperatures to reduce thermal noise interference in

data acquisition.Data Processing System: Processes

and analyzes the data received by the sensor,

generating usable images and information.

3 APPLICATION OF

PHOTOELECTRIC EFFECT IN

INFRARED REMOTE SENSING

TECHNOLOGY

3.1 Infrared Detectors

Infrared detectors utilize the internal photoelectric

effect to excite photons and convert them into

detectable electrical signals, characterized by fast

response speed and high sensitivity. When infrared

photons are incident on optoelectronic materials,

photons with energies greater than the band gap are

absorbed, causing electrons to jump from valence

bands to conduction bands, resulting in electron-hole

pairs. The resulting electron-hole pairs are separated

by an applied electric field, and the electrons move to

the positive electrode and the holes move to the

negative electrode, forming a photocurrent. The

magnitude of the photocurrent is proportional to the

intensity of the incident light, and the infrared signal

can be detected by measuring the photocurrent.

Currently, widely recognized and extensively used

infrared detectors include HgCdTe detectors, InSb

detectors, and quantum well infrared detectors.

HgCdTe detectors have high photon absorption

rates across the entire infrared spectrum and the

lowest dark current due to thermally excited carriers

at the same temperature, making them the most

important infrared detector material to date. However,

the detection performance of all photonic detectors is

limited by the internal thermal excitation noise and

the external background radiated noise. (Zeng,2012)

The research and development direction of cooled

infrared detectors of the French company Sofradir is

in the leading position in the world. In 2012, Sofradir

fabricated a 640×512 longwave red detector with a

pixel spacing of 15 m. At 90 K, the detector's Noise-

Equivalent Temperature Difference (NETD) can

reach 13

mK.(Qi,Feng,Chen,Ning,Liu,Sun&Kang,2022)

Application of the Photoelectric Effect in Infrared Remote Sensing Technology

287

InSb detectors, made from Ⅲ-V semiconductor

materials, offer good stability, with performance

unaffected by operating and storage time (Mu, 2023).

They have higher absorption coefficients and

sensitivity in the 3μm-5μm MWIR range and can

respond quickly, making them very suitable for

military applications such as night vision imaging,

target tracking, and precision guidance(Zhang, 2024).

Hu et al. (2022) designed a high-frame-rate mid-wave

indium antimonide infrared detector system, which

achieved 640×512 resolution image output at 200 Hz

frame rate, significantly improved the infrared image

uniformity and target tracking accuracy, and

demonstrated its excellent performance in high-speed

target detection and recognition.

The main body of the quantum well infrared

detector adopts an n-i-n longitudinal layered structure,

and the narrow bandgap material (such as GaAs) is

sandwiched between the wide bandgap material (such

as AlGaAs) to form a potential well, which restricts

the movement of electrons in the vertical direction

and quantizes their energy. In this design, the photons

of the incident light are absorbed by the electrons in

the quantum wells as they enter multiple quantum

well nanocomposite layers, and the electrons

transition from the ground state to the excited state.

The transition electrons are at a higher energy level in

the potential well and become free carriers. Under the

action of the external electric field, the electron or

thermal emission in the excited state tunnels from the

quantum well to the conduction band, forming a

photocurrent, and finally realizes the detection of

infrared light by the detector. This unique subband

transition method gives quantum well infrared

detectors uniform performance, low cost, and good

room-temperature operation, showing great

development potential(Liu, Dong & Lv, 2019).

3.2 Thermal Imaging Technology

Thermal imaging technology is an important

application of infrared remote sensing, utilizing the

photoelectric effect to convert infrared radiation from

target objects into visible images. Infrared thermal

cameras can capture 8μm-14μm infrared radiation

emitted by objects and convert it into visible images

based on temperature and emissivity differences.

These converted thermal images correspond to the

surface temperature distribution of the objects.

Currently, thermal imaging technology is widely used

in medical diagnosis, military reconnaissance, and

fire rescue, providing human eyes with a view of the

infrared spectrum and enhancing system observation

sensitivity, allowing people to obtain information

about the objective world and thermal

motion(You,2020).

3.3 Spectral Analysis

Spectral analysis is another important application

field of infrared remote sensing technology. Different

materials have unique spectral characteristics due to

their different emission and absorption properties of

infrared radiation. By analyzing these characteristic

infrared spectra, we can identify the material

composition and structure of target objects. The

photoelectric effect plays a crucial role in this process

by converting infrared radiation of different

wavelengths into different electrical signals,

providing the basis for researchers to obtain data for

spectral analysis. Infrared spectral analysis is

currently widely used in environmental monitoring,

mineral exploration, agriculture, and other fields. For

example, remote sensing spectral analysis of

grasslands can achieve grassland type classification,

forage assessment, and monitoring of grassland

degradation.

4 THE SHORTCOMINGS AND

DEVELOPMENT OF THE

APPLICATION OF THE

PHOTOELECTRIC EFFECT

Infrared remote sensing technology has been widely

used in many fields, but it still has many

imperfections and immaturity

4.1 Spatial Resolution Limitations

The spatial resolution of infrared remote sensing,

especially thermal infrared remote sensing, is

generally lower than that of visible remote sensing.

This is because the infrared wavelength is long and

the diffraction limit leads to low resolution at the

same aperture, which makes it difficult to identify

small targets (such as building details, small vehicles),

and relies on multi-source data fusion in fine mapping

or target recognition.

4.2 Susceptible to Atmospheric

Interference

Atmospheric absorption and scattering have a great

influence on infrared remote sensing, and gases such

as water vapor and carbon dioxide have strong

absorption of specific infrared bands (such as 3-5 μm,

IAMPA 2025 - The International Conference on Innovations in Applied Mathematics, Physics, and Astronomy

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8-14 μm), resulting in signal attenuation. At the same

time, infrared remote sensing also depends on the

weather, and clouds and haze will block infrared

radiation, especially in the long-wave infrared band,

and the data quality will be significantly reduced in

rainy weather.

4.3 The Complexity of the

Temperature-Radiation

Relationship

The emissivity difference is one of the important

factors affecting infrared remote sensing. the

emissivity of surface materials (such as metals,

vegetation, and water bodies) is very different, and

the radiation signals are different at the same

temperature, which needs to be accurately calibrated

to avoid misjudgment. The problem of mixing pixels

also affects the imaging of infrared remote sensing,

which can be difficult to interpret when the pixels

contain objects of different temperatures/materials

(e.g., areas with mixed buildings and vegetation in the

urban heat island effect).

For example, multispectral thermal infrared

remote sensing has been studied for nearly 50 years,

but due to the small number of channels of

multispectral sensors, the corresponding weight

function is wide, and the vertical resolution is low,

and its observation data is greatly affected by the

surface temperature and emissivity, atmospheric

temperature and humidity profile, etc., which makes

it difficult to obtain satisfactory accuracy of the

results of multispectral thermal infrared remote

sensing inversion under specific conditions such as

high atmospheric water vapor content and unknown

emissivity (Li et al., 2013; Li et al., 2016)

Although infrared remote sensing technology is

still facing many technical problems, with the

development and progress of science and technology,

scientific researchers are combining the most

advanced science and technology to continuously

improve and perfect infrared remote sensing

technology, making it more mature and more

convenient to serve the scientific research and

application needs of various fields

1. With the continuous advancement of

nanomaterial technology, the emergence of new

photoelectric materials brings new opportunities for

the application of the photoelectric effect in infrared

remote sensing technology. Graphene, as a new two-

dimensional material, shows great potential in the

field of infrared remote sensing. Its wide-spectrum

absorption characteristics, high carrier mobility, and

tunable bandgap structure make it an ideal material

for infrared detection.

2. Quantum Dot Infrared Detectors (QDIP)

represent another important development direction.

Quantum dot infrared detectors are similar in

structure and principle to quantum well infrared

detectors (QWIP): electrons emitted from the emitter

are captured by quantum dots or drift to the collector.

When infrared radiation excites electrons, the emitted

electrons gather at the collector under an external

electric field.

Quantum dot infrared detectors theoretically have

longer carrier capture and relaxation times than

quantum well infrared detectors, resulting in lower

dark current and higher photoresponse. Additionally,

QDIPs are sensitive to vertically incident light, have

effective carrier changes, and can operate for

extended periods at high temperatures (Song,2013).

The introduction of a sub-point absorber layer can

improve the absorption efficiency of the device for

near-red light, thereby improving the performance of

the device. Under the excitation of 808 nm

wavelength, the response of the device increased

from 7.62 m A/W to 19.9 m A/W without bias, and

the specific detection rate was achievable 4.86 ×



cm·H𝑧





·𝑊



.(Qu,2023)

3. The application of artificial intelligence

technology in remote sensing is also becoming

increasingly widespread. Super-resolution image

reconstruction, target recognition, and classification

can be achieved through deep learning algorithms

combined with artificial intelligence technology,

significantly improving the data processing

efficiency and intelligence level of infrared remote

sensing systems. This holds the promise of

developing more capable, efficient, and accurate

infrared remote sensing systems in the future.

5 CONCLUSION

As the foundation of infrared remote sensing

technology, the photoelectric effect plays a

significant role in infrared detectors, thermal imaging

systems, and spectral analysis. With the research on

new photoelectric materials such as graphene and

black phosphorus, and the development of quantum

dot technology and artificial intelligence, the

application of the photoelectric effect in infrared

remote sensing technology will further expand. The

integration of the photoelectric effect with emerging

technologies is expected to bring dramatic chemical

reactions in the field of infrared remote sensing,

Application of the Photoelectric Effect in Infrared Remote Sensing Technology

289

pushing the technology towards higher resolution,

higher sensitivity, and greater intelligence, and

bringing more innovative applications to military,

medical, agricultural, and geological fields.

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