Semiconductor Optoelectronic Materials—From 3D to 0D, from Classical Applications to Quantum Information

　　This work is aimed at next-generation optoelectronic information systems, developing novel preparation technologies for semiconductor optoelectronic functional materials to meet the demands of high-speed, integrated, and quantum-based semiconductor optoelectronic devices. The material preparation techniques employed include precision methods such as molecular beam epitaxy (MBE), metal-organic chemical vapor deposition (MOCVD), and atmospheric-pressure chemical vapor deposition (CVD). Device fabrication utilizes standard semiconductor processes and micro- and nano-fabrication technologies. Using MBE, we have prepared high-density 1.3-μm InAs/GaAs quantum-dot materials; lasers fabricated from these materials achieve a single-layer gain of 7 cm⁻¹, direct modulation rates exceeding 40 Gbps, stable output over a temperature range of 10–70℃, and a maximum operating temperature of 200℃. These lasers have already been deployed in fiber-optic communication networks. By combining micro-probe oxidation lithography with atomically hydrogen-assisted MBE or MOCVD, we have fabricated position-controlled quantum-dot arrays with a minimum inter-dot spacing of 50 nm and positioning accuracy of 3 nm, providing a technical solution for integrated single-photon sources used in quantum communications and all-optical quantum computing circuits. Using MOCVD, we have developed 1.3–1.55-μm quantum-dot single-photon sources with single-photon purity reaching the order of 0.001. With these single-photon sources, we have demonstrated quantum key distribution over a 120-km fiber-optic link. Based on a combination of MBE and MOCVD, we have fabricated InGaAs/GaAs/InGaP double-quantum-well lasers that achieve strong single-mode lasing at 1.064 μm with an output power of 500 mW. By leveraging frequency-doubling technology, we have created a continuous-wave 532-nm pure-green laser with an output power of 100 mW, offering an efficient solution for green light sources in laser displays. Using MOCVD, we have prepared InGaAsP/InP avalanche photodetector (APD) materials; APDs fabricated from these materials operate in Geiger mode with a photon detection efficiency exceeding 25% and a dark-count rate below 20 kHz—comparable to international standards. We have also developed a 32×32 single-photon detector array, further advancing the domestic production of single-photon focal-plane detectors. By employing atmospheric-pressure CVD, we have prepared Si-APD epitaxial materials; APD devices fabricated from these materials exhibit a maximum gain of up to 800—the highest reported globally—and a responsivity ranging from 300 to 600 A/W with excellent linearity, making them suitable for applications such as laser 3D imaging radar and laser-guided fuses. In summary, this study has carried out research and development of semiconductor optoelectronic materials, yielding a variety of high-performance materials—from three-dimensional bulk structures to zero-dimensional quantum dots—to meet diverse needs spanning from classical optoelectronic devices to quantum information systems.

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