PbS and PbSe Photodetectors
- Technology
- Infrared photodetectors
- Partner
- IR Materials
Infrared Materials’ PbS and PbSe photoconductive IR detectors are specialised semiconductor sensors designed to detect infrared radiation across wavelengths from about 0.7 µm up to 5.5 µm. These polycrystalline lead sulfide and lead selenide detectors are used in process control systems, gas analysers, optical spectrometers, and flame monitoring devices.
PbS detectors are optimised for short-wave IR sensitivity, typically in the 1–3 µm region, making them suitable for moisture analysis and low-level light monitoring. PbSe detectors cover the mid-wave IR region around 1–5 µm and are valued for their fast response times in real-time detection tasks such as flame or spark detection. Both detector types can operate at room temperature, while selected models include built-in thermoelectric coolers to reduce noise and improve detectivity.
This detector range provides a cost-effective alternative to other IR sensor technologies, especially where larger detector areas, high sensitivity, and robust industrial performance are required.
Range features
A high level overview of what this range offers
- Broad spectral coverage (0.7–5.5 µm): Detects both short-wave and mid-wave infrared signals for a wide range of sensing applications.
- Multiple package options: Available in TO-3, TO-5, TO-8, TO-37, and TO-66 hermetically sealed metal can packages for easy integration and environmental protection.
- Uncooled or TE-cooled configurations: Offered as ambient detectors or with 1- or 2-stage thermoelectric cooling for reduced noise and improved sensitivity.
- Fast response times: PbSe variants can achieve response times as low as approximately 2 µs for rapid IR event detection.
- High detectivity: Delivers strong signal-to-noise performance with detectivity up to approximately 3 × 10^11 cm·Hz^½/W.
- Cost-effective large-area sensing: Provides an economical alternative to some other IR detector technologies for larger sensing areas.
- Robust sealed design: Hermetically sealed construction with IR-transparent sapphire or silicon windows supports long-term stability in demanding environments.
- RoHS and REACH compliant: Manufactured using compliant materials and processes for environmental and regulatory alignment.
What’s in this range?
All the variants in the range and a comparison of what they offer
| Specification | Uncooled – PbS | Uncooled – PbSe | 1 or 2TE – PbS 2W | 1 or 2TE – PbSe 2W | 1 or 2TE – PbS 3W | 1 or 2TE – PbSe 3W |
|---|---|---|---|---|---|---|
Wavelength peak (µm) | 2.4 | 3.8 | 2.5 | 4.3 | 2.7 | 4.5 |
Time constant (µs) | 100 | 2 | 1250 | 9 | 1750 | 12 |
Package | TO-3, TO-5, TO-8 | TO-3, TO-5, TO-8 | TO-37 | TO-37 | TO-8, TO-66 | TO-8, TO-66 |
Detectivity D* (cm·Hz^½/W) | Up to 1 × 10^11 | Up to 2 × 10^10 | Up to 1.5 × 10^11 | Up to 3 × 10^10 | Up to 3 × 10^11 | Up to 3.5 × 10^10 |
FAQs
for PbS and PbSe Photodetectors
PbS and PbSe infrared detectors combine high sensitivity with fast response while operating at ambient temperatures. They provide effective IR signal detection without cryogenic cooling, making them a compact and cost-effective solution for many sensing applications.
Both PbS and PbSe photoconductive detectors can operate reliably at ambient temperatures up to around +85 °C. Standard operation does not require special cooling, while thermoelectric cooling is used to improve performance rather than extend the basic operating temperature range.
Yes. Detectivity can be improved by using optical concentration methods such as built-in micro lenses or external collector optics to focus more infrared radiation onto the detector element. This increases incident irradiance and can significantly enhance effective detectivity and signal output.
Yes. Multi-element versions are available, including multi-channel modules and array formats. These are suitable for applications that require simultaneous detection at multiple points or wavelengths, such as 4-channel PbSe detectors or linear array configurations.
Yes. PbS and PbSe photoconductive detectors are typically paired with low-noise preamplifier circuits to convert resistance changes into a usable electrical signal. Dedicated transimpedance amplifiers or amplifier modules help optimise sensitivity and ensure stable operation.
These detectors are used in industrial gas analysis, moisture measurement, flame and spark detection, FTIR spectroscopy, thermal imaging, and combustion monitoring. Their spectral sensitivity and stability make them suitable for accurate infrared measurements across industrial and scientific applications.
PbS and PbSe detectors enable real-time monitoring of process parameters through infrared absorption or emission signals. They can be used to measure moisture content, flame quality, or exhaust gas composition, helping improve product quality, energy efficiency, and operational safety.
Yes. Lead selenide detectors in particular offer microsecond-scale response times, making them well-suited to detecting fast infrared bursts such as ignition flashes, electrical discharges, sparks, or muzzle flashes. Their speed and IR sensitivity support reliable triggering in safety and defence-related systems.
