Characterization Techniques for Perovskite Solar Cell Materials

Characterization Techniques for Perovskite Solar Cell Materials
List of contributors
Preface
1 Bandgap tuning and compositional exchange for lead halide perovskite materials
	1.1 Introduction
	1.2 Organic/inorganic ion mixing
		1.2.1 Perovskite “black-phase” stability: role of cations
	1.3 Ion library
	1.4 Perovskite compositions in devices
	1.5 Band gap engineering strategy
	1.6 Lead replacement
	1.7 Anion exchange
	1.8 Conclusions
	References
2 X-ray diffraction and Raman spectroscopy for lead halide perovskites
	2.1 Introduction
		2.1.1 XRD and Raman spectroscopy
	2.2 Resonance Raman spectroscopy of halide substituted hybrid perovskites
	2.3 Raman spectroscopy probing bleaching and recrystallization process of CH3NH3PbI3 film
	2.4 Conclusions
	References
3 Optical absorption and photoluminescence spectroscopy
	3.1 Introduction
	3.2 Optical absorption spectroscopy
	3.3 Steady state UV–Vis–NIR spectroscopy
		3.3.1 Photothermal deflection spectroscopy (PDS)
		3.3.2 Estimation of the bandgap
			3.3.2.1 Simple calculation
			3.3.2.2 Tauc plots
		3.3.3 Near band edge trap states
		3.3.4 Absorption properties of metal-halide perovskites
		3.3.5 Light absorption process in metal-halide perovskites
		3.3.6 Excitons in metal-halide perovskites
		3.3.7 Tuning of the light absorption spectrum via chemical modifications in metal-halide perovskite
	3.4 Photoluminescence spectroscopy
		3.4.1 Processes involved in photoluminescence
		3.4.2 Diffusion length and carrier lifetime
		3.4.3 Photon recycling in metal-halide perovskites
		3.4.4 Exciton binding energy and excitonic peaks
		3.4.5 Tunability and stability of PL in alloyed perovskites
		3.4.6 Impact of perovskite crystalline quality, fluence and charge extraction layer on PL
		3.4.7 Temperature dependent PL in metal halide perovskite
	References
4 Current-voltage analysis: lessons learned from hysteresis
	4.1 “Hysterical” current-voltage behavior of perovskite solar cells
		4.1.1 Hysteria around hysteresis
		4.1.2 Scan-rate dependence
		4.1.3 Quantification of hysteresis: hysteresis indices
		4.1.4 Pre-conditioning & poling
	4.2 Origin of hysteresis
		4.2.1 Capacitive and non-capacitive origin of hysteresis
		4.2.2 The dielectric response of metal-halide perovskites
		4.2.3 Ionic defect formation & migration
		4.2.4 Modeling hysteresis
	4.3 A window into device operation
		4.3.1 Device architecture & selective contact layers
		4.3.2 Light and temperature dependence
		4.3.3 Perovskite layer morphology and composition
		4.3.4 Defect engineering, passivation and external ionic species
		4.3.5 Hysteresis and stability
	4.4 Conclusion and outlook
	References
5 Photoelectron spectroscopy investigations of halide perovskite materials used in solar cells
	5.1 Introduction
	5.2 Photoelectron spectroscopy
		5.2.1 Basic principles
		5.2.2 Core-level photoelectron spectroscopy
		5.2.3 Valence band photoelectron spectroscopy
	5.3 From UPS to HAXPES: variation of the photon excitation energy
	5.4 PES investigations of halide perovskite materials
		5.4.1 Precautions
			5.4.1.1 Binding energy calibration
			5.4.1.2 Sample preparation and handling
			5.4.1.3 Radiation damage
		5.4.2 Selected results
			5.4.2.1 Chemical characterization
			5.4.2.2 Electronic structure
			5.4.2.3 Energy level alignment
	5.5 Conclusions and outlook
	References
6 Time resolved photo-induced optical spectroscopy
	6.1 Introduction
	6.2 Fundamental processes within the perovskite film
		6.2.1 Processes at open circuit condition
		6.2.2 Processes at short circuit condition
		6.2.3 Devices under working conditions
	6.3 Light absorption and charge separation kinetics
	6.4 Charge recombination, transfer and transport kinetics
	6.5 Stark effects, defects and defect migration in perovskite solar cells
		6.5.1 Stark effects
		6.5.2 Dielectric relaxation
		6.5.3 Relevance to defects
		6.5.4 Comparison with other solar cell technologies
	6.6 Electron-phonon interactions and polarons in CH3NH3PbI3 perovskites
	6.7 Summary and outlook
	References
	Further reading
7 Photovoltage/photocurrent transient techniques
	7.1 Introduction
	7.2 Small modulation transient techniques
		7.2.1 Transient photo-voltage technique (TPV)
		7.2.2 Transient photo-current decay (TPC) and differential capacitance (DC)
		7.2.3 Square-wave modulation for photovoltage and photocurrent transients (SW-PVT and SW-PCT)
		7.2.4 Intensity-modulated photocurrent and photovoltage (IMPS and IMVS)
	7.3 Large modulation techniques
		7.3.1 VOC rise and decay
		7.3.2 Charge extraction (CE)
		7.3.3 Current interrupt voltage (CIV)
	7.4 Conclusions
	References
8 Temperature effects in lead halide perovskites
	8.1 Introduction
		8.1.1 Crystal structure and phase transitions
		8.1.2 Thermal expansion coefficients
		8.1.3 Optical properties
		8.1.4 Degradation at higher temperature
		8.1.5 Device performance
	References
9 Stability of materials and complete devices
	9.1 Introduction
	9.2 Stability testing
		9.2.1 Conventional testing
		9.2.2 Perovskite testing
			9.2.2.1 Initial efficiency testing
			9.2.2.2 Laboratory long-term stability testing
			9.2.2.3 Outdoor testing
	9.3 Perovskite stability
		9.3.1 Atmospheric water and oxygen stability
		9.3.2 Thermal stability
		9.3.3 Light stability
		9.3.4 Electric field stability
		9.3.5 Mechanical stability
	9.4 Device and interface stability
		9.4.1 Charge selective contacts
		9.4.2 Metal contact
	9.5 Conclusion and outlooks
	References
10 Characterizing MAPbI3 with the aid of first principles calculations
	10.1 Introduction
	10.2 Structure and bonding
	10.3 Phonons, anharmonicity and MA dynamics
	10.4 Electronic band structure and charge carrier dynamics
	10.5 Intrinsic point defects
	10.6 Conclusion
	References
11 Organic-inorganic metal halide perovskite tandem devices
	11.1 Introduction
	11.2 Multi junction solar cells
		11.2.1 Transparent conductive contact
		11.2.2 Recombination layer
	11.3 Perovskite tandem devices
	11.4 Theoretical calculations on the potential of perovskite tandem
	11.5 Perovskite/silicon tandem devices
	11.6 Perovskite/CIGS tandem devices
	11.7 Perovskite-perovskite tandem devices
	11.8 Outlook
	References
12 Concluding remarks
Index