Technology
Making Solar Energy Economically Viable


While Natcore’s "Liquid Phase Deposition" (LPD) process has many exciting potential applications, the company has decided to focus on the area where it appears to have the greatest impact: solar energy.


There are two initial applications in photovoltaics where the Company’s technology could yield very significant improvements in costs and efficiencies.


First, the Company’s liquid phase deposition technology promises to allow the solar cell industry to reduce silicon wafer thicknesses by up to two-thirds — an advancement that will dramatically improve throughput and profit margins.

The key advantage that Natcore’s liquid phase deposition process brings is its ability to grow the crucial anti-reflective (AR) layer of a solar cell in a mild chemical bath. Current Thermal Oxide technology requires relatively thick silicon wafers because of the high heat involved. Thinner wafers often warp in this harsh environment.


In contrast, Natcore’s mild process will allow wafers of only about one-third the thickness currently being used — which will translate to as much as two-thirds less silicon and significantly lower costs in materials and processing.


Because the AR coating is the final step in solar cell manufacturing, and because the liquid phase deposition process will utilize simple, low-cost tubs and a proprietary cartridge system, it is expected that Natcore’s process will fold easily into virtually any silicon cell production plant.


The Company plans to sell materials, deposition systems and licenses based on its technology to manufacturers of silicon solar cells.


Second,
and perhaps much more importantly, a highly compelling application of Natcore’s technology recently emerged:


The Company’s scientists have discovered that its liquid phase deposition process could allow, for the first time, mass manufacturing of super-efficient (30%+) tandem solar cells. For comparison purposes, these cells could achieve twice the power output of today’s most efficient solar cells.


Until now, these tandem cells have been producible only under lab conditions, and at very high costs. Natcore’s process has the potential to allow their mass production at a lower cost/watt than anything available today.


For reference, review the accompanying schematic of a third-generation, silicon-quantum dot tandem solar cell.


Natcore envisions its liquid phase deposition process allowing the manufacture of a tandem cell consisting of up to three cells arranged one on top the other, starting with an ordinary silicon solar cell on the bottom.


Something called a
cell interconnect comes next, then a second cell made of silicon quantum dots. This solar cell is tuned to absorb light in the middle of the spectrum, represented in the picture by the green color.


A second cell interconnect follows and a third cell, another silicon quantum dot device, sits on top. This uppermost cell is tuned to absorb the blue end of the spectrum.


The combination of all three operating in tandem would produce well over 30% efficiency — or about double the output of current technology.

Natcore’s edge in this process is the ability to embed the two types of silicon quantum dots in the two cells within a layer of silicon dioxide using our liquid-phase film growth process. All current and recent attempts to create viable tandem cells have used vacuum deposition techniques that are expensive and do not allow independent control over the formation of the quantum dots and the way they are arranged. That is a major disadvantage.


In fact, Natcore’s liquid phase deposition process is what makes it possible to even consider producing a tandem cell on a commercial scale, let alone in the lab. Not only that, the full device can also utilize the Company’s proprietary AR coating deposition process, thereby realizing additional production cost savings.


Through the combination of these two applications, Natcore hopes to bridge the economic gap between solar power and conventional energy production — an achievement that represents the “Holy Grail” of the alternative energy industry.