#Photovoltaic Technology Guides

Photovoltaic (PV) technology converts sunlight directly into electricity through the photoelectric effect. When photons with sufficient energy strike a semiconductor - typically silicon - they free electrons from their atomic bonds, creating an electric current. The amount of current depends on the number of photons, their energy relative to the material's bandgap, and the cell's ability to collect those freed electrons before they recombine and are lost.

Standard silicon PV technology comes in two main forms: monocrystalline silicon (typical panel efficiency 21 - 24%) and polycrystalline silicon (18 - 20%). Both share the same operating principles and spectral response characteristics, though monocrystalline cells generally show better performance at elevated temperatures and under low-irradiance conditions.

Beyond silicon, emerging architectures are pushing against the theoretical limits of single-junction cells. Perovskite-silicon tandem cells reached 34.85% certified efficiency in April 2025 (LONGi, NREL) by stacking two absorber materials with complementary bandgaps, allowing the top cell to capture UV and blue photons efficiently while silicon handles red and near-infrared. CIGS and CdTe thin-film technologies offer different tradeoffs, particularly in low-light and high-temperature performance.

These articles cover both the technology fundamentals and their practical performance implications for residential and commercial PV installations.

Lab efficiency records set the ceiling for what's commercially possible. The 34.85% tandem cell record (LONGi, NREL, 2025) contrasts with the 24.5% practical limit for single-junction silicon. Commercial production panels typically land 3 - 5 percentage points below their lab counterparts due to scaling, interconnection losses, and glass transmission. The gap between record and production efficiency is where most cell technology R&D investment is currently focused.