Both will use specially designed materials based on arrays of nanowires with uniform orientation. The main focus of the project will be on developing these nanostructured materials to optimize the efficiency of both the photovoltaic cell and the photoelectrochemical cell.

The researchers will use a technique called glancing angle deposition (GLAD) to fabricate the nanowire arrays.

Instead of requiring complex lithographic processing, GLAD uses computer-controlled substrate motion in conjunction with glancing incidence flux from physical vapour deposition to precisely tailor the structure of thin films. The geometry and porosity can be engineered to specific needs.

The goal is to produce clean energy. The idea of using solar energy and water as a source of hydrogen is very attractive, and we believe nanostructured materials can be used to do this efficiently.

We want to build a device that you can put in the sun, fill it with water, and get hydrogen without using any outside source of energy.

—Jin Zhang, professor of chemistry and biochemistry at UCSC and project lead

The hydrogen storage project, also involving UCSC and U of Georgia, with the addition of the Washington State University,  will also use the GLAD technique. One solution for hydrogen storage is to store it in  a solid form as a metal hydride compound. The researchers plan to find the optimum conditions for fabricating metal hydride nanostructures to achieve highly efficient hydrogen storage.

Both projects have received funding from the DOE.