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Lead iodide perovskite light-emitting field-effect transistor.

Chin XY, Cortecchia D, Yin J, Bruno A, Soci C - Nat Commun (2015)

Bottom Line: Here we show that screening effects associated to ionic transport can be effectively eliminated by lowering the operating temperature of methylammonium lead iodide perovskite (CH3NH3PbI3) field-effect transistors.Field-effect carrier mobility is found to increase by almost two orders of magnitude below 200 K, consistent with phonon scattering-limited transport.This demonstration of CH3NH3PbI3 light-emitting field-effect transistors provides intrinsic transport parameters to guide materials and solar cell optimization, and will drive the development of new electro-optic device concepts, such as gated light-emitting diodes and lasers operating at room temperature.

View Article: PubMed Central - PubMed

Affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.

ABSTRACT
Despite the widespread use of solution-processable hybrid organic-inorganic perovskites in photovoltaic and light-emitting applications, determination of their intrinsic charge transport parameters has been elusive due to the variability of film preparation and history-dependent device performance. Here we show that screening effects associated to ionic transport can be effectively eliminated by lowering the operating temperature of methylammonium lead iodide perovskite (CH3NH3PbI3) field-effect transistors. Field-effect carrier mobility is found to increase by almost two orders of magnitude below 200 K, consistent with phonon scattering-limited transport. Under balanced ambipolar carrier injection, gate-dependent electroluminescence is also observed from the transistor channel, with spectra revealing the tetragonal to orthorhombic phase transition. This demonstration of CH3NH3PbI3 light-emitting field-effect transistors provides intrinsic transport parameters to guide materials and solar cell optimization, and will drive the development of new electro-optic device concepts, such as gated light-emitting diodes and lasers operating at room temperature.

No MeSH data available.


FET characteristics.(a,b) Transfer (a) and output (b) characteristics obtained at 78 K. The n-type output characteristics (right panel) were measured at Vgs=40–100 V (Vgs=40 V black, Vgs=60 V red, Vgs=80 V blue, Vgs=100 V magenta), whereas the p-type output characteristics (left panel) are measured at Vgs=−40 V to −100 V (Vgs=−40 V black, Vgs=−60 V red, Vgs=−80 V blue, Vgs=−100 V magenta). Solid and dashed curves are measured with forward and backward sweeping, respectively. See Supplementary Information for the full set of FET characteristics as a function of temperature.
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f2: FET characteristics.(a,b) Transfer (a) and output (b) characteristics obtained at 78 K. The n-type output characteristics (right panel) were measured at Vgs=40–100 V (Vgs=40 V black, Vgs=60 V red, Vgs=80 V blue, Vgs=100 V magenta), whereas the p-type output characteristics (left panel) are measured at Vgs=−40 V to −100 V (Vgs=−40 V black, Vgs=−60 V red, Vgs=−80 V blue, Vgs=−100 V magenta). Solid and dashed curves are measured with forward and backward sweeping, respectively. See Supplementary Information for the full set of FET characteristics as a function of temperature.

Mentions: We found that reducing the operating temperature of our devices is an effective way to reduce hysteresis effects due to ionic transport/screening, allowing to record transport characteristics typical of conventional ambipolar semiconductor FETs (Fig. 2). The complete temperature evolution of ambipolar FET characteristics, from room temperature down to 78 K, is provided in Supplementary Figs 2 and 3 of the Supplementary Information. While above 198 K the output characteristics show either weak or no gate voltage dependence, at and below 198 K the devices display ‘textbook' n-type output characteristics. Similarly, typical p-type output characteristics are observed at 98 K and lower temperatures (Fig. 2b and Supplementary Fig. 3). Both p- and n-type transfer characteristics are independent of gate field from room temperature down to 258 K. This is reflected in the measurement by large hysteresis loops, which do not close when transitioning from the hole- to the electron-dominated transport gate voltage ranges and vice versa. Below 258 K, however, both n- and p-type transfer characteristics show a closed hysteresis loop. Hysteresis of n- and p-type transfer characteristics is substantially reduced below 198 and 98 K, respectively, consistent with the observation of ambipolar output characteristics (Fig. 2b and Supplementary Fig. 3). Induced carrier density of ∼3.8 × 1016 cm−2, maximum Ion/Ioff∼105 and current density of ∼830 A cm−2 (estimated for a ∼2 nm accumulation layer thickness) are obtained from standard transistor analysis at 198 K. These values are comparable to those previously reported for 2D hybrid organic–inorganic perovskites characterized at room temperature3940. Note that, although our low-temperature measurements clearly demonstrate the ambipolar nature of CH3NH3PbI3, previous studies have shown that carrier concentration can vary by up to six orders of magnitudes depending on the ratio of the methylammonium halide and lead iodine precursors and thermal annealing conditions, thus resulting in preferential p-type or n-type transport characteristics46.


Lead iodide perovskite light-emitting field-effect transistor.

Chin XY, Cortecchia D, Yin J, Bruno A, Soci C - Nat Commun (2015)

FET characteristics.(a,b) Transfer (a) and output (b) characteristics obtained at 78 K. The n-type output characteristics (right panel) were measured at Vgs=40–100 V (Vgs=40 V black, Vgs=60 V red, Vgs=80 V blue, Vgs=100 V magenta), whereas the p-type output characteristics (left panel) are measured at Vgs=−40 V to −100 V (Vgs=−40 V black, Vgs=−60 V red, Vgs=−80 V blue, Vgs=−100 V magenta). Solid and dashed curves are measured with forward and backward sweeping, respectively. See Supplementary Information for the full set of FET characteristics as a function of temperature.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4491174&req=5

f2: FET characteristics.(a,b) Transfer (a) and output (b) characteristics obtained at 78 K. The n-type output characteristics (right panel) were measured at Vgs=40–100 V (Vgs=40 V black, Vgs=60 V red, Vgs=80 V blue, Vgs=100 V magenta), whereas the p-type output characteristics (left panel) are measured at Vgs=−40 V to −100 V (Vgs=−40 V black, Vgs=−60 V red, Vgs=−80 V blue, Vgs=−100 V magenta). Solid and dashed curves are measured with forward and backward sweeping, respectively. See Supplementary Information for the full set of FET characteristics as a function of temperature.
Mentions: We found that reducing the operating temperature of our devices is an effective way to reduce hysteresis effects due to ionic transport/screening, allowing to record transport characteristics typical of conventional ambipolar semiconductor FETs (Fig. 2). The complete temperature evolution of ambipolar FET characteristics, from room temperature down to 78 K, is provided in Supplementary Figs 2 and 3 of the Supplementary Information. While above 198 K the output characteristics show either weak or no gate voltage dependence, at and below 198 K the devices display ‘textbook' n-type output characteristics. Similarly, typical p-type output characteristics are observed at 98 K and lower temperatures (Fig. 2b and Supplementary Fig. 3). Both p- and n-type transfer characteristics are independent of gate field from room temperature down to 258 K. This is reflected in the measurement by large hysteresis loops, which do not close when transitioning from the hole- to the electron-dominated transport gate voltage ranges and vice versa. Below 258 K, however, both n- and p-type transfer characteristics show a closed hysteresis loop. Hysteresis of n- and p-type transfer characteristics is substantially reduced below 198 and 98 K, respectively, consistent with the observation of ambipolar output characteristics (Fig. 2b and Supplementary Fig. 3). Induced carrier density of ∼3.8 × 1016 cm−2, maximum Ion/Ioff∼105 and current density of ∼830 A cm−2 (estimated for a ∼2 nm accumulation layer thickness) are obtained from standard transistor analysis at 198 K. These values are comparable to those previously reported for 2D hybrid organic–inorganic perovskites characterized at room temperature3940. Note that, although our low-temperature measurements clearly demonstrate the ambipolar nature of CH3NH3PbI3, previous studies have shown that carrier concentration can vary by up to six orders of magnitudes depending on the ratio of the methylammonium halide and lead iodine precursors and thermal annealing conditions, thus resulting in preferential p-type or n-type transport characteristics46.

Bottom Line: Here we show that screening effects associated to ionic transport can be effectively eliminated by lowering the operating temperature of methylammonium lead iodide perovskite (CH3NH3PbI3) field-effect transistors.Field-effect carrier mobility is found to increase by almost two orders of magnitude below 200 K, consistent with phonon scattering-limited transport.This demonstration of CH3NH3PbI3 light-emitting field-effect transistors provides intrinsic transport parameters to guide materials and solar cell optimization, and will drive the development of new electro-optic device concepts, such as gated light-emitting diodes and lasers operating at room temperature.

View Article: PubMed Central - PubMed

Affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.

ABSTRACT
Despite the widespread use of solution-processable hybrid organic-inorganic perovskites in photovoltaic and light-emitting applications, determination of their intrinsic charge transport parameters has been elusive due to the variability of film preparation and history-dependent device performance. Here we show that screening effects associated to ionic transport can be effectively eliminated by lowering the operating temperature of methylammonium lead iodide perovskite (CH3NH3PbI3) field-effect transistors. Field-effect carrier mobility is found to increase by almost two orders of magnitude below 200 K, consistent with phonon scattering-limited transport. Under balanced ambipolar carrier injection, gate-dependent electroluminescence is also observed from the transistor channel, with spectra revealing the tetragonal to orthorhombic phase transition. This demonstration of CH3NH3PbI3 light-emitting field-effect transistors provides intrinsic transport parameters to guide materials and solar cell optimization, and will drive the development of new electro-optic device concepts, such as gated light-emitting diodes and lasers operating at room temperature.

No MeSH data available.