@article{Werner2020b,

title = {Ultra-thin passivation layers in Cu(In,Ga)Se2 thin-film solar cells: full-area passivated front contacts and their impact on bulk doping},

author = {F Werner and B Veith-Wolf and M Melchiorre and F Babbe and J Schmidt and S Siebentritt},

doi = {10.1038/s41598-020-64448-9},

issn = {2045-2322},

year  = {2020},

date = {2020-05-05},

journal = {Scientific Reports},

volume = {10},

number = {1},

pages = {7530},

abstract = {In the search for highly transparent and non-toxic alternative front layers replacing state-of-the-art CdS in Cu(In,Ga)Se2 thin-film solar cells, alternatives rarely exceed reference devices in terms of efficiency. Full-area ultra-thin aluminium oxide tunnelling layers do not require any contact patterning and thus overcome the main drawback of insulating passivation layers. Even a few monolayers of aluminium oxide can be deposited in a controlled manner by atomic layer deposition, they show excellent interface passivation properties, low absorption, and suitable current transport characteristics on test devices. Depositing a ZnO-based transparent front contact, however, results in extremely poor solar cell performance. The issue is not necessarily a low quality of the alternative front layer, but rather the intricate relation between front layer processing and electronic bulk properties in the absorber layer. We identify three challenges critical for the development of novel front passivation approaches: (i) both Cd and Zn impurities beneficially reduce the high native net dopant concentration in the space charge region, (ii) sputter deposition of ZnO damages the passivation layer resulting in increased interface recombination, (iii) thermal treatments of devices with ZnO layer result in substantial Zn diffusion, which can penetrate the full absorber thickness already at moderate temperatures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gharibzadeh2020,

title = {2D/3D Heterostructure for Semitransparent Perovskite Solar Cells with Engineered Bandgap Enables Efficiencies Exceeding 25% in Four-Terminal Tandems with Silicon and CIGS},

author = {S Gharibzadeh and I M Hossain and P Fassl and B Abdollahi Nejand and T Abzieher and M Schultes and E Ahlswede and P Jackson and M Powalla and S Schäfer and M Rienäcker and T Wietler and R Peibst and U Lemmer and B S Richards and U W Paetzold},

doi = {10.1002/adfm.201909919},

year  = {2020},

date = {2020-05-01},

journal = {Advanced Functional Materials},

volume = {30},

number = {19},

pages = {1909919},

abstract = {Wide-bandgap perovskite solar cells (PSCs) with optimal bandgap (Eg) and high power conversion efficiency (PCE) are key to high-performance perovskite-based tandem photovoltaics. A 2D/3D perovskite heterostructure passivation is employed for double-cation wide-bandgap PSCs with engineered bandgap (1.65 eV ≤ Eg ≤ 1.85 eV), which results in improved stabilized PCEs and a strong enhancement in open-circuit voltages of around 45 mV compared to reference devices for all investigated bandgaps. Making use of this strategy, semitransparent PSCs with engineered bandgap are developed, which show stabilized PCEs of up to 25.7% and 25.0% in four-terminal perovskite/c-Si and perovskite/CIGS tandem solar cells, respectively. Moreover, comparable tandem PCEs are observed for a broad range of perovskite bandgaps. For the first time, the robustness of the four-terminal tandem configuration with respect to variations in the perovskite bandgap for two state-of-the-art bottom solar cells is experimentally validated.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Werner2020bb,

title = {Oxidation as Key Mechanism for Efficient Interface Passivation in Cu(In,Ga)Se_2 Thin-Film Solar Cells},

author = {F Werner and B Veith-Wolf and C Spindler and M R Barget and F Babbe and J Guillot and J Schmidt and S Siebentritt},

doi = {10.1103/PhysRevApplied.13.054004},

year  = {2020},

date = {2020-05-01},

journal = {Phys. Rev. Applied},

volume = {13},

number = {5},

pages = {054004},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Warren2020,

title = {A Taxonomy for Three-Terminal Tandem Solar Cells},

author = {E L Warren and W E McMahon and M Rienäcker and K T VanSant and R C Whitehead and R Peibst and A C Tamboli},

doi = {10.1021/acsenergylett.0c00068},

year  = {2020},

date = {2020-04-01},

journal = {ACS Energy Letters},

volume = {5},

number = {4},

pages = {1233-1242},

abstract = {Tandem and multijunction solar cells offer the only demonstrated path to terrestrial 1-sun solar cell efficiency over 30%. Three-terminal tandem (3TT) solar cells can overcome some of the limitations of two-terminal and four-terminal tandem solar cell designs. However, the coupled nature of the cells adds a degree of complexity to the devices themselves and the ways that their performance can be measured and reported. While many different configurations of 3TT devices have been proposed, there is no standard taxonomy to discuss the device structure or loading topology. This Perspective proposes a taxonomy for 3TT solar cells to enable a common nomenclature for discussing these devices and their performance. It also provides a brief history of three-terminal devices in the literature and demonstrates that many different 3TT devices can work at efficiencies above 30% if properly designed.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}