micro-pl

**Micro-PL** (Micro-Photoluminescence) is a **PL technique that uses a microscope objective to focus the laser to a diffraction-limited spot (~0.5-1 μm)** — enabling PL spectroscopy of individual nanostructures, quantum dots, single defects, and localized features. **How Does Micro-PL Work?** - **Objective**: High-NA microscope objective (50-100×) focuses the laser to ~1 μm spot. - **Confocal**: Optional confocal pinhole rejects out-of-focus light for improved spatial resolution. - **Cryogenic**: Often performed at low temperature (4-77 K) to sharpen spectral features. - **Single Emitters**: Can detect and characterize individual quantum dots, NV centers, or single molecules. **Why It Matters** - **Single Quantum Dots**: Measures individual QD emission energy, linewidth, and photon statistics. - **Nanowires**: Characterizes individual nanowire emission and composition gradients along the wire. - **Defect Identification**: Locates and spectroscopically identifies individual luminescent defects. **Micro-PL** is **PL through a microscope** — focusing the laser to a pinpoint to study the optical properties of individual nanostructures.