Page 10 - North American Clean Energy September October 2015

solar energy

Perovskite Solar Cells – The long and

short of it

By Dr. Xiaoxi He

PEROVSKITE PHOTOVOLTAICS are a breath of fresh air in are the majority. hose costs include glass sheets, junction
the photovoltaic market.
boxes, tabbing, encapsulates, sealants, and tempered glass

hey have experienced a remarkable improvement from back sheets. here is no large reduction potential for the

2.2% eiciency – how much of the light energy is used
price per unit area due to the manufacturing cost limit,

by the system per unit area - in 2006, (Toin University of which is predominantly determined by "other material”

Yokohama) to the latest record of 20.1% in 2014 (Korean costs. Outside of the module cost itself, (i.e., other hardware

Research Institute of Chemical Technology KRICT,
costs such as the balance-of-system costs) perovskite PVs
according to the latest eiciency records provided by the have no advantage over c-Si cells or other commercial thin-

National Renewable Energy Laboratory (NREL) in the US). ilm PV cells.

Perovskites have already surpassed organic photovoltaics However, in terms of the semiconductor material cost, the

(OPVs) and dye-sensitized solar cells (DSSCs) and are now, at active material cost of perovskites can be cheaper due to the

least in terms of eiciency, in the same range as leading thin lower cost of perovskite materials compared with CdTe. As
ilm PVs like cadmium telluride (CdTe) and copper indium the eiciency is further improved, the cost-per-watt can be

gallium selenide (CIGS).
decreased further.

High and rapidly improved eiciencies are not the only

advantage of perovskite solar cells. Flexibility, semi- Hybrid applications come irst

transparency, tailored form factors, better low-intensity light Perovskite solar cells will not compete with the dominate c-Si
performance, low potential processing cost, and low material cells in the short term due to their lack of maturity. Instead,

cost are other value propositions of perovskite solar cells. It’s however, perovskite solar cells can be combined with c-Si

no wonder why many companies and research institutions cells to further increase eiciency. By adding a perovskite

are strongly pursuing the technology.
solar cell on top of a c-Si cell, the total eiciency can be

improved to as high as 30%.
Cost-competitive vs. slim savings
In roof integrated installations where space is limited,

Perovskite solar cells are often compared to CdTe solar cells, the way to increase output is to improve the eiciency. he

which have the lowest manufacturing cost among thin-ilm c-Si PV market is hugely competitive now, which means

photovoltaic technologies. CdTe reported manufacturing that any improvement in eiciency will help manufacturers

costs of US$ 0.54 W-1 (or US$ 72 m-2) in the last quarter
distinguish themselves. he strong grid-connected market

of 2013, for an average eiciency of 13.4%, where "other drive explains why most companies working on perovskite
material” costs (which exclude semiconductor materials)
solar cells are targeting the utility market where the panels

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