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Nick Rolston

Nick Rolston

Ph.D. Stanford University, Applied Physics, in progress
B.S. University of Iowa, Physics, 2014
B.S. University of Iowa, Mathematics, 2014

Contact

Phone: 
(952) 594-1285
Office: 
Durand Building, Rm. 111

Reserach Interests

 

Strong, Stable, and Scalable Perovskite Solar Cells

Perovskite solar cells are a promising, low-cost, solution-processed solar technology that already exhibit high efficiencies, but suffer from challenging instabilities and degradation modes that limit their performance lifetimes. Our research in the Dauskardt Group focuses on improving the following characteristics:

 

Strength

intrinsically with perovskite chemistry

In their present planar design, perovskite solar cells are the most fragile class of cells ever tested, offering negligible resistance to fracture and limiting their commercial viability and path to market. The mechanical properties of state-of-the-art perovskite solar cells was studied, which have incorporated various cations to improve performance and chemical stability. The aim of this work was to understand how cation composition affected perovskite mechanical integrity and determine design criteria to increase cohesion and reliability toward the development of module-scale devices. Modest increases in cohesion were achieved with plastically deformable cations, but simply reducing defects or grain boundaries in perovskite films will not overcome their inherent fragility.

extrinsically with the Compound Solar Cell (CSC)

Instead of attempting to improve upon the intrinsically fragile nature of perovskites—which is related to their brittle, salt-like crystal structure—a new cell design that extrinsically shields the cells from mechanical stresses is proposed. Inspired by the compound eyes of insects comprising a close-packed array of independent photoreceptor units, a conventional solar cell is partitioned into a CSC by a scaffold into a vast array of smaller, encapsulated, mechanically shielded, and chemically contained perovskite microcells. The CSC is a new robust design partitioning a perovskite solar cell into an array of microcells with a mechanically-shielding scaffold to address both its mechanical fragility and chemical instability. The CSC represents an advance in the design of solution-processed devices, dramatically improving the resilience of chemically and mechanically unstable semiconductors.

Figure 1: top and side view of the Compound Solar Cell. The partitioning scaffold (gray) shields the fragile perovskite microcell array from mechanical stress. The individual microcells in the array are connected in parallel by the top and bottom electrode. Scaffold-partitioned cells increase mechanical resilience more than 30 times than planar perovskite while achieving comparable efficiencies on an area-adjusted basis.

Stability

with organosilicate barrier films

The obstacle limiting the successful commercialization of perovskites is producing large-scale, environmentally stable devices. Tuning perovskite compositions with various cation compositions has improved stability to an extent—although state-of-the-art perovskites are not fully resistant to heat and moisture—and there is a need for cheap, scalable, thin-film encapsulation techniques. Using a one-step spray-plasma process in open air, flexible submicron organosilicate barrier films are rapidly printed on large areas.  Barrier films deposited on perovskite solar cells dramatically improve resistance to heat, moisture, and light and represent a facile approach for packaging stable perovskite modules.

Figure 2: The barrier deposition method used was a variation of rapid spray plasma processing (RSPP), in which an organosilicate and fluorinated toluene precursor were mixed and sprayed at the leading edge of a compressed air plasma. The spray and plasma were swept over the entire device to create submicron barrier films that dramatically improve thermal and moisture stability of perovskite solar cells.

Scalability

with Rapid Spray-Plasma Processing (RSPP)

Although efficiencies of perovskite solar cells have surpassed 22%, the active area used is generally ~0.1 cm2. Innovative nucleation and growth of perovskite films by plasma reactive species led to the development of a scalable method, RSPP, to produce efficient and robust photoactive perovskite in open air at rates of > 1 cm/s with considerable advantages in terms of throughput, raw material usage, and manufacturability. Using the Stanford Synchrotron Lightsource, in-situ characterization of RSPP perovskite films is performed to study growth kinetics and to understand the mechanisms behind perovskite conversion. RSPP opens new lines of scientific inquiry regarding perovskite reliability and implementation to large-scale processes.

Figure 3: Photograph of a perovskite film deposited by RSPP on 930 cm2 glass in under 4 min.

 

Publications

  • W.J. Scheideler, N. Rolston, O. Zhao, J. Zhang, & R.H. Dauskardt, “Rapid Aqueous Spray Fabrication of Robust NiO: A Simple and Scalable Platform for Efficient Perovskite Solar Cells”, submitted.

  • L. Bertoluzzi, N. Rolston, K.A. Bush, B.C. O’Regan, & M.D. McGehee, “Energy diagram and mobile ion concentration in lead halide perovskite solar cells”, in review.

  • A.D. Printz, O. Zhao, N. Rolston, S.S. Hamann, O. Solgaard, & R.H. Dauskardt, “Multifunctional immersion lens arrays for patterning, automatic alignment, and photon management in compound perovskite solar cells”, submitted.

  • M.Q. Hovish, N. Rolston, F. Hilt, Q. Xiao, & R.H. Dauskardt, “Open air plasma deposition of superhydrophilic titania coatings”, in review.

  • S.I. Na, Y.H. Seo, Y.C. Nah, S.S. Kim, H. Heo, J.E. Kim, N. Rolston, R.H. Dauskardt, M. Gao, Y. Lee, & D. Vak, “High performance roll-to-roll produced fullerene-free organic photovoltaic devices via temperature-controlled slot die coating”, in review.

  • N. Rolston*, K.A. Bush*, A.D. Printz, A. Gold‐Parker, Y. Ding, M.F. Toney, M.D. McGehee, & R.H. Dauskardt, “Engineering stress in perovskite solar cells to improve stability”, Advanced Energy Materials, 2018, DOI: 10.1002/aenm.201802139 (*Equal contribution)

  • D. Angmo, X. Peng, J. Cheng, M. Gao, N. Rolston, K. Sears, C. Zuo, J. Subbiah, S.S. Kim, H.C. Weerasinghe, R.H. Dauskardt, & D. Vak, “Beyond fullerenes: Indacenodithiophene-based organic charge transport layer towards upscaling of low-cost perovskite solar cells”, ACS Applied Materials & Interfaces, 2018, DOI: 10.1021/acsami.8b04861. 

  • K.A. Bush*, N. Rolston*, A. Gold-Parker, S. Manzoor, J. Hausele, Z.J. Yu, J.A. Raiford, R. Cheacharoen, Z.C. Holman, M.F. Toney, R.H. Dauskardt, & M.D. McGehee, “Controlling thin-film stress and wrinkling during perovskite film formation”, ACS Energy Letters, 2018, DOI: 10.1021/acsenergylett.8b00544 (*Equal contribution)

  • L. Zhao, N. Rolston, K.M. Lee, X. Zhao, M.A. Reyes‐Martinez, N.L. Tran, Y.W. Yeh, N. Yao, G.D. Scholes, Y.L. Loo, A. Selloni, R.H. Dauskardt, & B.P. Rand, “Influence of bulky organo-ammonium halide additive choice on the flexibility and efficiency of perovskite light-emitting devices”, Advanced Functional Materials, 2018, DOI: 10.1002/adfm.201802060.

  • S.G. Prolongo, A.D. Printz, N. Rolston, B.L. Watson, & R.H. Dauskardt, “Poly (triarylamine) composites with carbon nanomaterials for highly transparent and conductive coatings”, Thin Solid Films, 2018, DOI: 10.1016/j.tsf.2017.11.025.

  • N. Rolston, A.D. Printz, J.M. Tracy, H. Weerasinghe, D. Vak, L.J. Haur, A. Priyadarshi, N. Mathews, D.J. Slotcavage, M.D. McGehee, R.E. Kalan, R.L. Grimm, H. Tsai, W. Nie, A.D. Mohite, S. Gholipour, M. Saliba, M. Graetzel, & R.H. Dauskardt, “Effect of cation composition on the mechanical stability of perovskite solar cells”, Advanced Energy Materials, 2018, DOI: 10.1002/aenm.201702116.

  • F. Hilt, M.Q. Hovish, N. Rolston, & R.H. Dauskardt, “Rapid route to efficient, scalable, and robust perovskite photovoltaics in air”, Energy and Environmental Science, 2018, DOI: 10.1039/C8EE01065J

  • R. Cheacharoen, N. Rolston, D. Harwood, K.A. Bush, R.H. Dauskardt, & M.D. McGehee, “Design and understanding of encapsulated perovskite solar cells to withstand thermal cycling”, Energy and Environmental Science, 2018 , DOI: 10.1039/C7EE02564E.

  • N. Rolston, A.D. Printz, F. Hilt, M.Q. Hovish, K. Bruening, C.J. Tassone, & R.H. Dauskardt, “Improved stability and efficiency of perovskite solar cells with submicron flexible barrier films deposited in air”, Journal of Materials Chemistry A, 2017, 10.1039/C7TA09178H.

  • B.L. Watson*, N. Rolston*, A.D. Printz*, & R.H. Dauskardt, “Scaffold-reinforced perovskite compound solar cells”, Energy and Environmental Science, 2017, DOI: 10.1039/C7EE02185B (*Equal contribution).

  • B.L. Watson*, N. Rolston*, L. Taleghani, K.A. Bush, & R.H. Dauskardt, “Synthesis and use of a hyper-connecting cross-linking agent in the hole-transporting layer of perovskite solar cells”, Journal of Materials Chemistry A, 2017, DOI: 10.1039/C7TA05004F (*Equal contribution)

  • N. Rolston, A.D. Printz, S.R. Dupont, E. Voroshazi, & R.H. Dauskardt, “Effect of environmental stressors on decohesion kinetics of organic solar cells”, Solar Energy Materials and Solar Cells, 2017, DOI: 10.1016/j.solmat.2017.06.002.

  • K.A. Bush*, A.F. Palmstrom*, Z.J. Yu*, M. Boccard, R. Cheacharoean, J.P. Mailoa, D.P. McMeekin, R.L.Z. Hoye, C.D. Bailie, T. Leijtens, I.M. Peters, M.C. Minichetti, N. Rolston, R. Prasanna, S. Sofia, D. Harwood, W. Ma, F. Moghadam, H.J. Snaith, T. Buonassisi, Z.C. Holman, S.F. Bent, & M.D. McGehee, “23.6%-efficient monolithic perovskite/silicon tandem solar cells with improved stability”, Nature Energy, 2017, DOI: 10.1038/nenergy.2017.9 (*Equal contribution)

  • J.H. Kim, I. Lee, T.S. Kim, N. Rolston, B.L. Watson, & Reinhold H. Dauskardt, “Understanding mechanical behavior and reliability of organic electronic materials”, MRS Bulletin, 2017, DOI: 10.1557/mrs.2017.3.

  • W. Greenbank, N. Rolston, E. Destouesse, G. Wantz, L. Hirsch, R.H. Dauskardt, & S. Chambon, “Improved mechanical adhesion and electronic stability of organic solar cells with thermal ageing: the role of diffusion at the hole extraction interface”, Journal of Materials Chemistry A, 2017, DOI: 10.1039/C6TA09665D.

  • N. Rolston, B.L. Watson, C.D. Bailie, M.D. McGehee, J.P. Bastos, R. Gehlhaar, J.E. Kim, D. Vak, A.T. Mallajosyula, G. Gupta, A.D. Mohite, & R.H. Dauskardt, “Mechanical integrity of solution-processed perovskite solar cells”, Extreme Mechanics Letters, 2016, DOI: 10.1016/j.eml.2016.06.006.

  • B.L. Watson, N. Rolston, K.A. Bush, T. Leijtens, M.D. McGehee, & R.H. Dauskardt, “Cross-linkable, solvent-resistant fullerene contacts for robust and efficient perovskite solar cells with increased JSC and VOC”, ACS Applied Materials & Interfaces, 2016, DOI: 10.1021/acsami.6b06164.

  • M. Corazza, N. Rolston, R.H. Dauskardt, S.A. Gevorgyan, & F.C. Krebs, “Role of stress factors on the adhesion of interfaces in R2R fabricated organic photovoltaics”, Advanced Energy Materials, 2016, DOI: 10.1002/aenm.201501927.

  • H.C. Weerasinghe, N. Rolston, D. Vak, A. Scully, & R.H. Dauskardt, “A stability study of printed organic photovoltaic modules containing a polymeric electron-selective layer”, Solar Energy Materials and Solar Cells, 2016, DOI: 10.1016/j.solmat.2016.03.034.

  • V. Balcaen, N. Rolston, S.R. Dupont, E. Voroshazi, & R.H. Dauskardt, “Thermal cycling effect on mechanical integrity of inverted polymer solar cells”, Solar Energy Materials and Solar Cells, 2015, DOI: 10.1016/j.solmat.2015.07.019.

Other manuscripts from PhD work are in various stages of preparation and submission.

Patents

  • US Patent 15943085 “Mechanical matrix for enhancing the thermomechanical and chemical reliability of optoelectronic device technologies” B.L. Watson, N. Rolston, A.D. Printz, & R.H. Dauskardt, October 4, 2018.

  • US Patent 15874527 “Method for forming perovskite layers using atmospheric pressure plasma” F. Hilt, M.Q. Hovish, N. Rolston, & R.H. Dauskardt, July, 19, 2018.

  • US Provisional Application 62/628624 “Lens array for the patterning of photoresist by maskless lithography” N. Rolston, A.D. Printz, S.S. Hamann, O. Solgaard, & R.H. Dauskardt, February 9, 2018.

  • US Provisional Application 62/479803 “Synthesis and use of azide-functionalized nodes for cross-linking materials containing organic components” B.L. Watson, N. Rolston, & R.H. Dauskardt, March 31, 2017.

Conference Proceedings and Presentations

  • I. Lee, N. Rolston, & R.H. Dauskardt, “Understanding molecular weight effect on low-temperature processed hole transport layer (PTAA) for robust wearable electronics” eWear Symposium, Stanford, CA, September 13, 2018.

  • O. Zhao, A.D. Printz, N. Rolston, S.S. Hamann, O. Solgaard, & R.H. Dauskardt, “Multifunctional lens arrays for patterning and photon management in compound perovskite solar cells” eWear Symposium, Stanford, CA, September 13, 2018.

  • N. Rolston, A.D. Printz, J.M. Tracy, R.H. Dauskardt, “Effect of composition and microstructure on the mechanical stability of perovskite solar cells” IEEE Photovoltaics Specialists Conference, Waikoloa, HI, June 14, 2018.

  • N. Rolston, A.D. Printz, F. Hilt, M.Q. Hovish, K. Bruning, C.J. Tassone, & R.H. Dauskardt, “Spray plasma processing of barrier films deposited in air for improved stability of flexible electronic devices”, IEEE International Interconnect Technology Conference, Santa Clara, CA, June 4, 2018. DOI: 10.1109/IITC.2018.8430405

  • A. Printz, N. Rolston, S.S. Hamann, O. Zhao, O. Solgaard, & R.H. Dauskardt, “Scaffold-reinforced perovskite compound solar cells with integrated light management”, Materials Research Society Spring Meeting, Phoenix, AZ, April 6, 2018.

  • M.Q. Hovish, F. Hilt, N. Rolston, K. Bruening, & R.H. Dauskardt, “Scalable and rapid spray plasma processing of single and multiple cation perovskites”, Materials Research Society Spring Meeting, Phoenix, AZ, April 6, 2018.

  • N. Rolston, A.D. Printz, J.M. Tracy, R.H. Dauskardt, “Effect of composition and microstructure on the mechanical stability of perovskite solar cells”, Materials Research Society Spring Meeting, Phoenix, AZ, April 5, 2018.

  • N. Rolston, A.D. Printz, F. Hilt, M.Q. Hovish, K. Bruning, C.J. Tassone, & R.H. Dauskardt, “Spray plasma processing of barrier films deposited in air for improved stability of flexible electronic devices”, Materials Research Society Spring Meeting, Phoenix, AZ, April 4, 2018. Best poster award nominee 

  • N. Rolston, A.D. Printz, J. Tracy, H.C. Weerasinghe, D. Vak, B.L. Watson, & R.H. Dauskardt, “Effect of composition and microstructure on stability of perovskite solar cells” Australian Center for Advanced Photovoltaics Conference, Melbourne, Australia, December 7, 2017.

  • N. Rolston, A.D. Printz, B.L. Watson, & R.H. Dauskardt, “Improved reliability of organic and perovskite solar cells” Australasian Community for Advanced Organic Semiconductors Symposium, Gold Coast, Australia, December 6, 2017.

  • N. Rolston, A.D. Printz, J. Tracy, & R.H. Dauskardt, “Effect of composition and microstructure on the mechanical stability of perovskite solar cells” Bay Area Photovoltaics Consortium Fall Meeting, Berkeley, CA, 

  • N. Rolston, B.L. Watson, A.D. Printz, & R.H. Dauskardt, “Scaffold-reinforced perovskite compound solar cells for improved stability” Global Climate and Energy Project Student Lecture, Stanford, CA, July 24, 2017.

  • N. Rolston, A.D. Printz, F. Hilt, M.Q. Hovish, & R.H. Dauskardt, “Improved efficiency and stability of perovskite solar cells with submicron barrier films deposited in air” Bay Area Photovoltaics Consortium Spring Meeting, Stanford, CA, May 22, 2017.

  • F. Hilt, M.Q. Hovish, N. Rolston, & R.H. Dauskardt, “Ultrafast one-step deposition of perovskite thin films by atmospheric plasma curing” Materials Research Society Spring Meeting, Phoenix, AZ, April 20, 2017.

  • A.D. Printz, N. Rolston, B.L. Watson, & R.H. Dauskardt, “New concepts in reinforced, segmented perovskite solar cell design with polymer scaffolding” Materials Research Society Spring Meeting, Phoenix, AZ, April 18, 2017. Best poster award nominee

  • N. Rolston, A.D. Printz, F. Hilt, M.Q. Hovish, B.L. Watson, & R.H. Dauskardt, “Processes for robust, scalable, and stable perovskite solar cells” Materials Research Society Spring Meeting, Phoenix, AZ, April 17, 2017.

  • N. Rolston, F. Hilt, M.Q. Hovish, A.D. Printz, & R.H. Dauskardt, “Atmospheric plasma deposition for stable, scalable, and robust perovskite solar cells” American Chemical Society Spring Meeting, San Francisco, CA, April 4, 2017.

  • N. Rolston, A.D. Printz, B.L. Watson, & R.H. Dauskardt, “Reinforced perovskite solar cells designed with integrated polymer scaffolding for robust, efficient photovoltaics” American Chemical Society Spring Meeting, San Francisco, CA, April 2, 2017.

  • B.L. Watson, N. Rolston, K.A. Bush, A.D. Printz, & R.H. Dauskardt, “Overcoming the mechanical fragility of perovskite solar cells using novel cross-linking chemical additives and scaffolds” American Chemical Society Spring Meeting, San Francisco, CA, April 2, 2017.

  • N. Rolston, B.L. Watson, A.D. Printz, & R.H. Dauskardt, “Next-generation robust perovskite solar cells for improved stability” International Conference on Perovskite Solar Cells and Optoelectronics, Genoa, Italy, September 28, 2016.

  • N. Rolston, B.L. Watson, & R.H. Dauskardt, “Reinforcing perovskites for improved mechanical stability of solar cells” Materials Research Society Spring Meeting, Phoenix, AZ, March 31, 2016.

  • N. Rolston, B.L. Watson, & R.H. Dauskardt, “Thermomechanical properties of perovskite solar cells” Materials Research Society Spring Meeting, Phoenix, AZ, March 28, 2016.

  • N. Rolston, B.L. Watson, & R.H. Dauskardt, “Crosslinkable Materials for Increased Thermomechanical Reliability of Perovskite Solar Cells” KAUST Solar Future Conference, Thuwal, Saudi Arabia, November 8, 2015.

  • N. Rolston, B.L. Watson, & R.H. Dauskardt, “Improved Mechanical Stability of Perovskite Solar Cells”, Bay Area Photovoltaics Consortium Fall Meeting, Berkeley, CA, October 20, 2015.

  • N. Rolston, V. Balcaen, S.R. Dupont, E. Voroshazi, & R.H. Dauskardt, “Thermal Cycling of Polymer Solar Cells”, Materials Research Society Spring Meeting, San Francisco, CA, April 8, 2015.

Awards

  • National Science Foundation Graduate Research Fellowship (2015-2018)

  • Ford Foundation Graduate Research Fellowship (2015-2019)

  • National Defense Science and Engineering Graduate Fellowship

  • Stanford EDGE-STEM Fellowship (2015-2017)