Technology | NextGen Nano

Current technology makes solar panels limited in their application. They are expensive, brittle and cumbersome. Limited efficiency means large surface areas are required to provide any meaningful power generation, which must be supplemented by a centralised power source. NextGen Nano’s patented, proprietary technology results in highly-efficient, flexible solar panels applied to structures with wafer-thin, robust application. This advancement allows transportation vehicles and other applications to greatly supplement their power reserves.

NextGen Nano’s polymer semiconductors are alterable in material design, lightweight, flexible, semi-transparent, and potentially inexpensive. Combining organic semiconductors and photovoltaics results in an exciting class of energy harvesting technique – polymer solar cells (PSCs). From a commercial point of view, the payback period of PSCs is projected to be less than that of other photovoltaic products. The following figure demonstrates its working mechanism. The light-absorbing layer is the heart of all polymer solar cells. It is made by an organic mixture and sandwiched between two conducting electrodes. The layer absorbs solar energy and converts the energy into electrical power. The optimised thickness of the active layer is in the range of hundreds of nanometres.

Transparent solar cells (TSCs) have attracted extensive attention due to their potential for integration into solar windows, automobile windshields and self-powered electronic devices. The potential market size is increasing tremendously in recent years. In conventional solar cells, the incoming light enters the solar cell and is reflected by the metal mirror, therefore doubling the optical path within the light harvesting materials. While in the case of TSC, light absorption is reduced significantly due the transparent electrode. This leads to an inevitable loss in the photocurrent and thus the efficiency. To enhance the photon collection in a TSC, especially in the IR region, photonic crystal structure such as distributed Bragg reflectors (DBR) can be placed on top of the transparent electrode. DBR is made of periodic array combining a low refractive index layer and high refractive index layers. Light is partially refracted, reflected, and transmitted at each interface. The lattice spacing, and the layer refractive indexes define whether the interference between the reflected or transmitted beams is constructive or destructive at a specific wavelength. The figure below illustrates a 1D photonic crystal array that serve as a good mirror for IR region. It selectively reflects a major portion of IR light while keeping a high visible light transmittance. DBR can be easily deposited by thermal evaporation or low-temperature solution processing that imposed no degradation on the solar cells underneath.

In most organic solar cells, they harvest light of a narrow spectral region. Ideally, we would like to broaden light harvesting covering the entire visible as well as the IR spectral region. One way it can be done is by fabricating a double junction cell with a front cell harvesting short wavelength light and the back cell harvesting long wavelength light. Figure 2 shows such a device with the FTAZ:IT-M layer harvesting short wavelength light and the PTB-7:IEICO-4F layer harvesting long wavelength light. The challenge of making such a device is the interconnection layer between the two cells and it is extremely difficult to do that by solution processing. We invented a new method of making an interconnection layer and it is highly reproducible. Recently, Philips 66 has expressed interest licensing our technology and we are in the process negotiating with them.

ECONOMIC
AND EARTH-FRIENDLY

Breakthrough technology replaces existing solutions fabricated using expensive finite pollutant materials with earth-friendly biopolymers.

EFFICIENCY

Potential to set a new high bar worldwide in record efficiencies for organic solar

TRANSPARENCY, FLEXIBILITY, ROBUSTNESS

Replaces traditional solar cells, which are brittle, opaque, heavy and rigid. NextGen technology is robust and can be applied to flexible surfaces whilst maintaining transparency

MULTIPLE APPLICATIONS

Unique physical properties open the potential
for a multitude of real-world applications, making the limitless solar power source more usable
and cost-effective than ever before.