Interfacial engineering and alternative device architectures for perovskite photovoltaics

Anthropogenic climate change largely caused by burning fossil fuels for energy generation is a major threat to the well-being of people and nature. Converting sunlight directly into electricity using photovoltaic (PV) devices provides a safe, renewable energy source for a sustainable future. Metal halide perovskites have established themselves as a transformative material for PV devices due to their unique combination of desirable properties including strong absorption coefficients, low nonradiative recombination rates, long carrier diffusion lengths, and low-cost solution-based fabrication. These properties could allow perovskite solar cells to revolutionize the PV industry from building integrated-PV to utility-scale solar cell deployment. All-back-contact (ABC) architectures, where both the selective contacts are micropatterned on one side of the absorber, represent untapped potential for higher efficiency perovskite PV devices by mitigating optical losses. In this thesis, ABC perovskite solar cells were developed using various microfabrication and thin film deposition techniques. Complementary interface formation processes are critical in ABC architectures because the n-type and p-type selective contacts are simultaneously exposed during processing. UV-ozone exposure followed by thermal annealing simultaneously reduced the defect density of the NiOx hole-selective contact and removed residual organic contamination on the TiO2 electron-selective contact. Next, the relative n-type and p-type selective contact areas were varied systematically using photolithography to study the impacts on ABC performance. Time and spatially resolved photoluminescence spectroscopy revealed greater recombination rates near the p-type NiOx-perovskite interface compared to the n-type SnO2-perovskite interface. Thus, a greater SnOx/NiOx area ratio improved performance by limiting recombination with the NiOx-perovskite interface and decreasing the distance electrons must travel laterally over the NiOx contact. Finally, cracked film lithography was demonstrated to be a cost-effective alternative to conventional photolithography to form an interconnected, defect-tolerant back-contact electrode network. Crack widening techniques were developed to tune the geometry, optical transparency, and sheet resistance to optimize device performance, showing the promise of cracked film lithography for scalable manufacturing of ABC perovskite solar cells. Building-integrated PV can transform buildings from energy sinks into energy efficient components of the modern built environment. Solution-based perovskite processing allows the ability to tune the visible transmittance to make semitransparent PV cells for use in PV windows. The perovskite absorber thickness was reduced to provide sufficient visible transmittance, but the resulting red transmissive color is undesirable for most architectural applications. To overcome this, one-dimensional photonic crystals were designed and fabricated to simultaneously balance the transmissive color to neutral grey and boost photocurrent and efficiency by reflecting red photons back into the PV cells. This work has led to an efficient and architecturally relevant PV window technology. A final contribution was leading a collaborative and comprehensive review on sustainable deployment of perovskite-based photovoltaics, identifying key priorities for research efforts in reducing, recycling, and remanufacturing to make perovskite PV one of the most sustainable energy sources on the market.

Name thesis:degree_name

Doctor of Philosophy (Ph.D.)

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Chemical and Biological Engineering

Grantor dc:publisher

Colorado School of Mines. Arthur Lakes Library

Year dc:date.issued

2023

Author dc:creator

• Prince, Kevin J.

Advisors dc:contributor.advisor

• Wolden, Colin Andrew
• Wheeler, Lance

Committee members dc:contributor.committeemember

• Agarwal, Sumit
• Samaniuk, Joseph R.
• Sellinger, Alan

• all-back-contact
• interfaces
• perovskites
• photovoltaics
• semiconductors
• solar cells

Statement dc:rights

• Copyright of the original work is retained by the author.

Language dc:language.iso

eng, English

Identifier

T 9626

OAI identifier oai:identifier

oai:repository.mines.edu:11124/178634