The solar industry has matured in the last 40 years. The National Energy Research Lab (NERL) data published in 2014 provides a summary of advances made in solar PV conversion cells.
As it is clear in Figure 1, the last three dacades have seen significant increase in the efficiency of the solar PV conversion, primarily because of material science research and development in mono-crystal, poly-crystal, multi-crystal, amorphous and thin film solar cells by developing PN junction from III-V and II-VI materials in the periodic table of elements. However, the dominant technology is based on Si doped with tri-valent and penta-valent impurities and generating indirect band-gap solar cell and GaAs (III-V) direct band-gap solar cells. The multi-junction solar cells are used to enhance the efficiency of the solar cells, but their production cost is much higher than Si solar cells.
The cost of solar cell production still prohibits the grid parity which is the economic hurdle preventing broad use of solar PV panels. The subsidies provided by the federal energy programs are not a sustainable solution to bring grid parity.
The Photonic Solar Conversion (PSC) technology exploits the mass-produced Si solar cells with innovative photonics to enhance efficiency and power generation by 2 to 3 times. PSC can enhance efficiency of a poly Si solar cell from 12% to 24% to 30%.