Duncan Clark, NextGen Nano: The Future of Tandem Solar Cells

Research from the nanotechnology
specialist company NextGen Nano suggests the viability of accelerating development
of high efficiency organic photovoltaic technology.

Studies conducted by NextGen Nano suggest
that a simple material known as HSolar is widely compatible with multiple solar
cell materials, serving as an interconnecting layer (ICL) in tandem solar
cells. HSolar also showed potential in terms of stability and efficiency in
tests replicated by several independent research teams.

Outlined in a paper recently
published in the Advanced Energy Materials journal, the research is a
vital step in the development of high efficiency organic photovoltaic (OPV)
technology, enabling future research teams to fabricate and develop
increasingly effective multi-junction OPVs. Results gathered from NextGen Nano
simulations indicates that efficiency in excess of 22% may be achievable in the
near future, based on these findings.

As Duncan Clark, NextGen
Nano’s Director of Operations explained, widespread implementation of OPV
technology is integral to realising a brighter, more sustainable future. Unfortunately,
development of organic solar technology has faced significant challenges in
terms of efficiency and replication, hindering commercialisation. Researchers
from NextGen Nano have taken step to overcome these obstacles, demonstrating OPV
efficiency in ways that can be replicated by third parties.

Led by research scientist Dr Carr
Ho and Dr Franky So, NextGen Nano’s Chief Technology Officer, the research
team’s main objective was to find ways of improving OPV efficiency. Traditionally,
development of OPVs has been curtailed by the narrow absorption bands of organic
semiconductor materials. Numerous researchers have broached this issue,
creating OPV technology capable of achieving higher efficiencies by layering
complementary subcells to create a multi-junction (MJ) OPV device.

The ICL serves as an electrical and
physical contact between subcells, which is vital in reducing energy loss. The ICL’s
efficiency is integral to the MJ solar device’s function. To date, developing
an ICL which does not interfere with other layers has presented significant
problems. The NextGen Nano team also had to overcome difficulties in terms of promoting
efficient charge recombination without diminution in open-circuit voltage, as
well as producing replicable results.

In its recent study, the NextGen
Nano team demonstrated a new type of ICL comprising Zinc Oxide and HSolar. The
ICL is relatively simple to produce commercially from raw materials. In
testing, NextGen Nano’s device demonstrated a power conversion efficiency of approximately
14.7%.

The NextGen Nano team shared these
results with other research teams, with the ultimate aim of validating the repeatability
of its findings. Third party research teams achieved similar efficiencies of up
to 16.1%. Simulations performed by the NextGen Nano team suggested that it may
be possible to increase efficiency by up to 22% by utilising advanced organic
photoactive materials to serve as tandem cells.

Matthew Stone, NextGen Nano’s Chairman, is committed to pioneering research into the
development of new, clean technologies through the implementation of
nanotechnology. NextGen Nano has strived to advance OPV technology for some
time, contributing to the next generation of dynamic, high-performance solar
panels.