We report up-converting (Yb,Er)2O3 thin films grown with the atomic layer deposition (ALD) technique. The films are crystalline and show a homogeneous morphology with a roughness less than 1nm for 40nm thick films. High-intensity near-infrared (NIR) to green and red two-photon up-conversion emission is obtained with 974nm excitation through an absorption by Yb3+, followed by a Yb3+-Er3+ energy transfer and emission from Er3+. The ALD technique promises to be excellent for producing up-converting films for many applications such as near-infrared radiation absorbing layers for solar cells and sensors in point-of-care biomedical diagnostics. Schematic picture of the ALD-grown (Yb,Er)2O3 thin film including the up-conversion emission spectra.
- Atomic layer deposition
- Thin film