Enabling Low-Cost and Broadband Infrared Sensing

Quantum Dot Infrared Photodetectors (QDIPs) outperform traditional infrared (IR) sensing technologies such as mercury cadmium telluride (HgCdTe) and indium antimonide (InSb) photodetectors in terms of cost, broadband response, and integration flexibility-critical for emerging IR sensing applications. According to SPIE's 2025 Infrared Technology Report, colloidal quantum dot (CQD)-based QDIPs achieve a broadband response covering the short-wave IR (SWIR, 1–3 μm), mid-wave IR (MWIR, 3–5 μm), and long-wave IR (LWIR, 8–14 μm) bands, whereas HgCdTe detectors are limited to narrow spectral ranges (e.g., MWIR only) without complex heterostructure design. QDIPs also offer a 70% cost reduction compared to HgCdTe detectors, as they can be fabricated via low-temperature solution processes (e.g., spin-coating, inkjet printing) on flexible substrates, eliminating the need for expensive epitaxial growth. Additionally, QDIPs exhibit a detectivity (D*) of 1×10¹¹ Jones at 5 μm-comparable to InSb detectors (2×10¹¹ Jones)-while operating at room temperature, avoiding the high cooling costs of cryogenically cooled HgCdTe systems.

A Canadian research team announced a major breakthrough in QD material engineering in Q4 2025, published in ACS Nano. By developing a core-shell-shell quantum dot structure (PbS/CdS/ZnS) with surface ligand passivation using 1,2-ethanedithiol (EDT), the team achieved a quantum yield of 92%-a 40% improvement over conventional PbS QDs (66%). The passivated QDs also exhibit enhanced environmental stability, retaining 90% of their photoluminescence intensity after 6 months of air exposure (vs. 50% for unpassivated QDs). This breakthrough boosts the QDIPs' responsivity to 8 A/W at 3 μm, surpassing commercial InSb detectors (5 A/W) at room temperature.

Meanwhile, a U.S.-based startup developed a roll-to-roll (R2R) fabrication process for large-area QDIP arrays. By optimizing the ink formulation (QD concentration, solvent viscosity) and printing parameters, the company produced 10 cm×10 cm QDIP arrays with a pixel density of 320×240 and a uniformity error of ±3%-a significant improvement over the industry average of ±8%. The R2R process reduces manufacturing costs by 55% compared to traditional photolithography-based methods, enabling QDIPs to be cost-competitive for consumer electronics applications, according to the IEEE Journal of Selected Topics in Quantum Electronics 2025 Technical Report. The resulting QDIP arrays achieve a response time of 50 ns, meeting the requirements for high-speed IR imaging.

In the consumer electronics sector, QDIPs are being integrated into smartphone cameras for enhanced low-light and IR imaging. A Chinese electronics manufacturer launched a flagship smartphone with a QDIP-based IR camera, which can capture clear images in complete darkness (0 lux) and detect temperature differences of 0.5°C-enabling applications such as night vision, food temperature monitoring, and skin health analysis. The QDIP module is 40% smaller and 30% lighter than traditional IR camera modules, fitting seamlessly into the smartphone's slim design.

In the industrial inspection field, QDIPs are used for non-destructive testing (NDT) of materials. A German automation firm deployed QDIP-based IR imaging systems in automotive manufacturing, detecting microcracks in metal components and delaminations in composite materials with a detection accuracy of 99.2%-a 15% improvement over conventional NDT systems. For medical imaging, a U.S. healthcare company developed a portable QDIP-based SWIR imaging device for vascular visualization, which can penetrate 5 mm of human tissue to map blood vessels without contrast agents, reducing patient discomfort and procedure time by 40%.

In the environmental monitoring sector, QDIPs' broadband response enables multi-gas detection. A European environmental technology firm launched a QDIP-based gas sensor that can simultaneously detect CO₂, CH₄, and NO₂ with a detection limit of 1 ppm-surpassing traditional electrochemical sensors (5 ppm). The sensor's low power consumption (10 mW) and small form factor (2 cm×2 cm) make it suitable for deployment in IoT-based air quality monitoring networks.

The commercialization of QDIPs is hindered by three core challenges: long-term stability under harsh conditions, high dark current, and limited scalability for high-resolution arrays. Under high-humidity environments (85% RH, 25°C), conventional QDIPs suffer a 25% reduction in responsivity after 1,000 hours, requiring expensive encapsulation layers (e.g., Al₂O₃ thin films) that increase module costs by 18%. Dark current density (1×10⁻⁶ A/cm²) is still 10 times higher than HgCdTe detectors, limiting their performance in low-light conditions.

Market-wise, global QDIP production is in the early commercialization stage, accounting for only 4% of the total IR photodetector market in Q4 2025. Major manufacturers such as FLIR Systems, Hamamatsu, and Thorlabs are investing in QDIP technology, but mass adoption is expected to start in 2028. Supply chain constraints also exist-high-purity quantum dots (99.99%) and specialized printing equipment are dominated by a few overseas suppliers, leading to a 10-week delivery cycle and a 28% cost premium. Additionally, there is a lack of unified international standards for QDIP performance testing (e.g., detectivity, spectral response), which hinders market acceptance and cross-industry collaboration.