Since January 1993, Progress in Photovoltaics has published six monthly listings of the highest confirmed efficiencies for a range of photovoltaic cell and module technologies [1-3]. By providing guidelines for the inclusion of results into these tables, this not only provides an authoritative summary of the current state of the art but also encourages researchers to seek independent confirmation of results and to report results on a standardised basis. In version 33 of these tables , results were updated to the new internationally accepted reference spectrum (IEC 60904-3, Ed. 2, 2008), where this was possible.
The most important criterion for inclusion of results into the tables is that they must have been independently measured by a recognised test centre listed elsewhere . A distinction is made between three different eligible definitions of cell area: total area, aperture area and designated illumination area, as also defined elsewhere . ‘Active area’ efficiencies are not included. There are also certain minimum values of the area sought for the different device types (above 0.05 cm2 for a concentrator cell, 1 cm2 for a one-sun cell and 800 cm2 for a module).
Results are reported for cells and modules made from different semiconductors and for subcategories within each semiconductor grouping (e.g. crystalline, polycrystalline and thin film). From version 36 onwards, spectral response information is included when available in the form of a plot of the external quantum efficiency (EQE) versus wavelength, either as absolute values or normalised to the peak measured value. Current–voltage (I–V) curves have also been included where possible from version 38 onwards.
2 NEW RESULTS
Highest confirmed ‘one-sun’ cell and module results are reported in Tables 1 and 2. Any changes in the tables from those previously published  are set in bold type. In most cases, a literature reference is provided that describes either the result reported or a similar result (readers identifying improved references are welcome to submit to the lead author). Table 1 summarises the best measurements for cells and submodules, whereas Table 2 shows the best results for modules. Table 3 contains what might be described as ‘notable exceptions’. Although not conforming to the requirements to be recognised as a class record, the cells and modules in this table have notable characteristics that will be of interest to sections of the photovoltaic community, with entries based on their significance and timeliness.
Table 1. Confirmed terrestrial cell and submodule efficiencies measured under the global AM1.5 spectrum (1000 W/m2) at 25 °C (IEC 60904-3: 2008, ASTM G-173-03 global).
AIST, Japanese National Institute of Advanced Industrial Science and Technology; NREL, National Renewable Energy Laboratory; FhG-ISE, Fraunhofer-Institut für Solare Energiesysteme; ESTI, European Solar Test Installation.
To encourage discrimination, Table 3 is limited to nominally 10 entries with the present authors having voted for their preferences for inclusion. Readers who have suggestions of results for inclusion into this table are welcome to contact any of the authors with full details. Suggestions conforming to the guidelines will be included on the voting list for a future issue.
Table 4 shows the best results for concentrator cells and concentrator modules (a smaller number of notable exceptions for concentrator cells and modules additionally are included in Table 4).
Table 4. Terrestrial concentrator cell and module efficiencies measured under the ASTM G-173-03 direct beam AM1.5 spectrum at a cell temperature of 25 °C.
Eleven new results are reported in the present version of these tables. The first new result in Table 1 documents a small improvement in the performance of a 1-cm2 CuInxGa1 − xSe2 (CIGS) cell to 19.8%. The cell was fabricated and measured at the US National Renewable Energy Laboratory (NREL). This also represents an outright record for any polycrystalline thin-film cell, slightly better than the 19.6% result reported for a CdTe cell in the previous version of these Tables. A second new result in Table 1 represents a significant improvement in the performance of a small CIGS submodule (minimodule) to 18.7%. The four-cell minimodule was fabricated by Solibro  and measured at the Fraunhofer Institute for Solar Energy Systems. The third new result in Table 1 records a slight improvement in efficiency to 10.8% for a 1-cm2 microcrystalline silicon cell fabricated and measured by the Japanese National Institute of Advanced Industrial Science and Technology (AIST) .
The fourth new result in Table 1 represents a new record for energy conversion efficiency for a reasonably large-area 399-cm2 dye-sensitised submodule fabricated by Sharp , with an efficiency of 8.8% measured at AIST. Along with other emerging technology devices, the stability of this device was not investigated, although the stability of related devices is reported elsewhere [8, 9]. The fifth new result in Table 1 is for a small submodule, with an improved efficiency of 8.5% measured for a 25-cm2 four-cell organic minimodule cell fabricated by Toshiba  and measured at AIST. Again, the stability of this device was not investigated, although the stability of earlier devices is also reviewed elsewhere [11, 12]. An earlier 6.8% result for a much larger organic cell submodule (396 cm2) fabricated by Toshiba, first appearing in version 41 of these tables, is also reinstated.
The final new result in Table 1 represents a new outright record for the conversion of the global solar spectrum by any photovoltaic device. An efficiency of 38.8% has been measured by NREL for a five junction cell fabricated by Spectrolab. The details of an earlier device demonstrating 37.8% efficiency are to be reported in an upcoming issue of the IEEE Journal of Photovoltaics. The top three higher bandgap subcells were grown inverted on a GaAs substrate while the bottom two subcells were grown upright on an InP substrate. After polishing and bonding, the GaAs substrate was removed.
A new result in Table 2 is a new record for a large-area a-Si/a-SiGe/nc-Si module (a, amorphous; nc, nanocrystalline, also referred to as microcrystalline). A stabilised efficiency of 10.9% is reported for a 1.4-m2 module of this type fabricated by LG Electronics  and measured at AIST.
An additional new result in Table 3 is an increase to 20.8% efficiency for a small-area 0.5-cm2 CIGS cell fabricated by the Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg  and measured by the Fraunhofer Institute for Solar Energy Systems. The cell area is too small for classification of this result as an outright record for a CIGS cell, with this now at 19.8% efficiency (Table 1). Research solar cell efficiency targets in US [], Japanese [] and European [] programs, for example, generally have been specified in terms of a minimum cell area of greater than 1 cm2. The 20.8% result is only slightly higher in efficiency than a 20.65% result also reported for a CIGS cell of similar size fabricated and measured at NREL.
A second new result in Table III is an improvement to 12.0% efficiency for a small area copper-zinc-tin-sulphide/selenide (CZTSS) cell fabricated by IBM and measured at the Newport Technology and Application Center, improving upon the 11.1% result reported earlier by the same group.
Table 4 reports two new results for concentrator cells and systems. A new record of 22.8% is reported for a 0.1-cm2 thin-film CIGS cell operating at a concentration of 15.4 suns (direct irradiance of 15.4 kW/m2). The cell was fabricated and measured at NREL, improving upon an earlier 21.5% result for a similar cell from the same group . The final new result in Table 4 is the confirmed measurement of a concentrator photovoltaic module with energy conversion efficiency above 35%. An efficiency of 35.9% was measured by NREL for a 1092-cm2 aperture area concentrator module fabricated by Amonix , under conditions approximating draft IEC standard 62670-1 ‘Concentrator Standard Test Conditions’ (1000 W/m2 direct irradiance, 25 °C cell temperature).
The EQE spectra for the new dye and organic submodule results as well as for the four new CIGS cell results and the CZTSS cell result reported in the present issue of these tables are shown in Figure 1(a). Figure 1(b) shows the EQE for the new nc-Si cell and a-Si/a-SiGe/nc-Si module results.
Figure 2 shows the current density–voltage (J–V) curves for the corresponding devices. For the case of modules, the measured current–voltage data have been reported on a ‘per cell’ basis (measured voltage has been divided by the known or estimated number of cells in series, whereas measured current has been multiplied by this quantity and divided by the module area). For the concentrator cell, the current density has been normalised to 1000 W/m2 irradiance by dividing by the sunlight concentration ratio.
Although the information provided in the tables is provided in good faith, the authors, editors and publishers cannot accept direct responsibility for any errors or omissions.
The Australian Centre for Advanced Photovoltaics commenced operation in February 2013 with support from the Australian Government through the Australian Renewable Energy Agency (ARENA). Responsibility for the views, information or advice expressed herein is not accepted by the Australian Government.