Visual Appearance of Nanocrystal-Based Luminescent Solar Concentrators

Area of Science:

• Materials Science
• Optics
• Sustainable Energy

Background:

• Building-integrated photovoltaics (BIPV) utilize luminescent solar concentrators (LSCs) as semitransparent plates for windows and facades.
• Current LSC research primarily focuses on electric power generation, neglecting optical properties impacting visual comfort.

Purpose of the Study:

• To evaluate state-of-the-art nanocrystals as luminophores for LSC windows.
• To assess the impact of LSC luminophores on visual comfort by analyzing color rendering properties.

Main Methods:

• Monte Carlo simulations were employed to analyze eight different nanocrystal candidates.
• LSC windows with varying transparency (50%-90%) were simulated.
• Color rendering index (CRI) and correlated color temperature (CCT) were used to assess color properties.

Main Results:

• Luminophores with wide visible absorption bandwidths maintained high CRI (>85) and near-Planckian CCT, even at high concentrations.
• Partial visible spectrum absorption in luminophores led to color distortion, indicated by low CCT and CRI values.
• High transmittance did not prevent color distortion with suboptimal luminophores.

Conclusions:

• Nanocrystal selection is critical for LSC window performance, balancing energy generation with visual comfort.
• Wide absorption bandwidths in visible spectrum are key for maintaining natural light quality through LSC windows.
• LSC technology can be optimized for BIPV applications by considering both optical and electrical characteristics.