Record amorphous silicon single-junction photovoltaic module with 9.1% stabilized conversion efficiency on 1.43 m²

Abstract

Providing two-thirds of the total stabilized power of thin-film tandem MICROMORPH TM technology, the amorphous junction remains a key element in the quest for higher efficiencies. This paper reports and summarizes a considerable work to achieve a record large-area amorphous silicon single-junction photovoltaic module. New hardware has been developed and known process steps have been accurately tuned and combined with new features of cell design. Effort was focused on the deposition of high-quality and low-defect a-Si:H layers that has promoted an improved device stability and resistance against light induced degradation. Efficient light management has been used, and module design has been revised. The word-record performance reported in this paper for a large-area (1.43 m 2 ) stabilized module conversion efficiency (total area) was measured and certified by Swiss PV Module Test Center to be 9.1%.

Theoretical evaluation of contact stack for high efficiency IBC-SHJ solar cells

“…To overcome such limitation, one can alternatively use doped wide bandgap thin-film Si films alloyed with carbon or oxygen that can induce stronger band bending than doped a-Si:H layers. In fact, a p-type contact stack featuring wide E g,p material such as SiO x :H (1.7 -2.2 eV) [24], [25], [55] and SiC x :H (1.4 -2.1eV) [20], [48], [75] exhibits maximized band bending at c-Si (see Figure 13 (right), where ΔE ~ 0). As a result, the use of wide bandgap doped p-type layer as incubation layer potentially boosts both FF and V OC as reported in Table 2.…”

“…Based on thin-film Si alloys, the use of silicon heterojunction (SHJ) structures has become particularly interesting to industry for the low thermal budget fabrication process. Besides, this PV technology benefits from the tremendous experience the field acquired from thin-film Si PV applications, which offer flexibility in a wide range of fabrication parameters [17]- [20]. The combination of c-Si and thin-film Si-based materials has therefore resulted in outstanding V OC values between 740 and 760 mV [15], [21], [22], anticipating record efficiency solar cells.…”

Numerical Design of Ultrathin Hydrogenated Amorphous Silicon-Based Solar Cell

“…Indeed, they observed that exposure to the light of an a-Si:H-based solar cell, stretched over time, caused a drop of its electrical parameters: this is known as a lightinduced degradation (LID) effect. This limitation can be reduced by controlling the thickness of the intrinsic (i) layer in the structure of solar cell [13,14]. In the a-Si:H-based solar cell, the thickness of the i-layer controls the short-circuit current [3].…”

Nanomirror-Embedded Back Reflector Layer (BRL) for Advanced Light Management in Thin Silicon Solar Cells

“…However, the commercially available stabilized efficiency and reliability of a-Si:H solar cells are greater than many of the third generation solar cells as reported so far. However, the main drawback of a-Si:H solar cells is light-induced degradation (LID), which can be minimized by controlling the thickness of the intrinsic (i) layer. − Normally, the LID decreases with decreasing the thickness of the i-layer, but the thickness of the i-layer cannot be lowered abruptly to minimize the LID as there are many other factors associated with this layer like absorption of light, etc. Among the three main layers of a-Si:H solar cell, the thickness of the i-layer controls the short-circuit current ( I sc ) and the thickness of the p- and n-layers along with their doping parameters determine the open circuit voltage ( V oc ) and short-circuit current ( I sc ).…”