Record 12.34% stabilized conversion efficiency in a large area thin‐film silicon tandem (MICROMORPH™) module

Abstract

Mass-adoption of thin-film silicon (TF-Si) photovoltaic modules as a renewable energy source can be viable if the cost of electricity production from the module is competitive with conventional energy solutions. Increased module performance (electrical power generated) is an approach to reduce this cost. Progress towards higher conversion efficiencies for 'champion' large area modules paves the way for mass-production module performance to follow. At TEL Solar AG, Trübbach, Switzerland, significant progress in the absolute stabilized module conversion efficiency has been achieved through optimized solar cell design that integrates high-quality amorphous and microcrystalline TF-Si-deposited materials with efficient light management and transparent conductive oxide layers in a tandem MICROMORPH ™ module. This letter reports a world record large area (1.43 m 2 ) stabilized module conversion efficiency of 12.34% certified by the European Solar Test Installation; an increase of more than 1.4% absolute compared with the previous record for a TF-Si triple junction large area module. This breakthrough result generates more than 13.2% stabilized efficiency from each equivalent 1 cm 2 of the active area of the full module.

Power Measurement of MICROMORPH Tandem Modules—An Overview

“…This approach led to the confirmation of a tandem module efficiency of 12.34% [67]. This result is in good agreement at different laboratories and is included in the latest version of the efficiency table v.46 from May 2015 [66].…”

“…Our world record of 12.34% stabilized module efficiency were confirmed by ESTI working with the outdoor characterization method for multijunction Gen5 modules and reported elsewhere [66], [67]. The overall methodology is very similar from AIST and TEL Solar with the main difference that the performance measurement is done outdoors on a two-axis tracker.…”

Advances in Thin-Film Si Solar Cells by Means of SiOx Alloys

“…The a-SiO x :H films were deposited at 40 MHz, using a gas mixture composed of SiH 4 , CO 2 , and H 2 , held at a pressure of 500 mTorr. The SiH 4 flow rate was kept constant at 6 sccm, whereas CO 2 and H 2 flow rates were varied in the range 0.5-4 sccm and 40-160 sccm, respectively.…”

“…Phosphorus doped n-type nc-SiO x :H (n-SiO x ) films were deposited at 13.56 MHz using H 2 , SiH 4 , CO 2 , with the addition of PH 3 as doping gas. The CO 2 /SiH 4 gas flow rate ratio was varied in the range 0-5, while keeping the PH 3 /(PH 3 + SiH 4 ) doping ratio fixed at 2%, the H 2 /SiH 4 flow rate ratio at 200, the pressure at 1.9 Torr, and the plasma power density at 40 mW/cm 2 .…”

“…In addition, for a more efficient use of light across the solar spectrum, multi-junction architectures have to be considered, by stacking thin component cells dedicated to the absorption of specific portions of the spectrum. Within the thin-film Si technology the highest efficiencies are indeed obtained with multi-junction devices, already starting with the very promising micromorph (amorphous silicon/microcrystalline silicon-a-Si:H/µc-SiH) tandem combination, for which a confirmed record efficiency of 12.3% has been demonstrated on large area modules (1.4 m 2 ) [2].…”