Solar cell materials with more than one bandgap offer the possibility to increase the efficiency of the solar cell beyond that of a single bandgap cell. One way to realize such solar cells is by making solar cells based on so-called intermediate band (IB) materials, that have three (or more) bandgaps in a single material.

At NTNU we are following several routes for the realization of IB materials: We are for example trying to make quantum dot (QD) nano-materials for QD-IBSCs, by growing III-V based semiconductors (i.e. GaAs based materials) using molecular beam epitaxy (MBE) at the Department of Electronics and Telecommunication (IET).  

We also have activities on “bulk” (macroscopic) IB materials, where the IB is formed by doping; i.e. doped ZnS, Cu₂O, TiO₂ and Si. Here we use pulsed laser deposition (PLD) to deposit doped and undoped materials at IFY, or we use ion implantation for the doping of (Si and TiO₂) single crystals or thin films at external facilities.

We fabricate simple devices using NTNU Nanolab and test them using a solar simulator or a flash lamp.  In addition, we simulate solar cell performance, of both ideal and more realistic IBSCs.

Ongoing projects

Ox-IB

The Oxide-based intermediate band (OX-IB) project aims to develop materials for so-called intermediate band solar cells for renewable electricity generation. The research includes a new approach to the design of new intermediate band materials made of oxides. The materials will be studied both theoretically and experimentally, and we also aim to make simple solar cell devices.

SUSOLTECH

SUSOLTECH (Research Center for Sustainable Solar Cell Technology) is a Research Centre for Environment-friendly Energy Research. SUSOLTECH joins the leading Norwegian research groups in solar cell technologies with leading companies in the solar cell industry. The overall goal of the Centre is to increase the size and number of jobs in the domestic solar cell industry.

Completed projects

HighQ-IB

In the High Efficiency Quantum Dot Intermediate Band Solar Cells (HighQ-IB) project, we will optimalize quantum dot materials for so called intermediate band solar cells.

SoRoSol

The Socially Robust Solar Cells (SoRoSol) project is aimed at building a platform for socially robust development of new high efficiency solar cell technologies.

Solar United

The Norwegian Research Centre for Solar Cell Technology joins scientific and industrial players in the field of photovoltaic technology with the aim of further developing the strong, Norwegian photovoltaic industry and substantially contributing towards making solar energy a significant renewable energy source.

Nano 3G-PV

The Nanomaterials for 3rd Generation Solar Cells project aims to develop intermediate-band solar cells based on quantum dots. The intermediate-band device is among the candidates for a third generation solar cell technology, having an upper limit for the efficiency that is twice that of curr ent devices used for terrestrial electricity production. Third generation solar cells used either as flat panels or in concentrator systems will potentially make solar electricity a major (i.e. cost competitive) contributor in global electricity production in this century.