Interstitial Doping of SnO_(2) Film with Li for Indium-Free Transparent Conductor

SnO_(2)films exhibit significant potential as cost-effective and high electron mobility substitutes for In_(2)O_(3)films.In this study,Li is incorporated into the interstitial site of the SnO_(2)lattice resulting in an exceptionally low resistivity of 2.028×10^(-3)Ω·cm along with a high carrier concentration of 1.398×10^(20)cm^(-3)and carrier mobility of 22.02 cm^(2)/V·s.

Effects of active layer thickness on performance and stability of dual-active-layer amorphous InGaZnO thin-film transistors

Dual-active-layer(DAL)amorphous InGaZnO(IGZO)thin-film transistors(TFTs)are fabricated at low temperature without post-annealing.A bottom low-resistance(low-R)IGZO layer and a top high-resistance(high-R)IGZO layer constitute the DAL homojunction with smooth and high-quality interface by in situ modulation of oxygen composition.The performance of the DAL TFT is significantly improved when compared to that of a single-active-layer TFT.A detailed investigation was carried out regarding the effects of the thickness of both layers on the electrical properties and gate bias stress stabilities.It is found that the low-R layer improves the mobility,ON/OFF ratio,threshold voltage and hysteresis voltage by passivating the defects and providing a smooth interface.The high-R IGZO layer has a great impact on the hysteresis,which changes from clockwise to counterclockwise.The best TFT shows a mobility of 5.41 cm^2/V·s,a subthreshold swing of 95.0 mV/dec,an ON/OFF ratio of 6.70×10^7,a threshold voltage of 0.24 V,and a hysteresis voltage of 0.13 V.The value of threshold voltage shifts under positive gate bias stress decreases when increasing the thickness of both layers.

Strain-enhanced polarization sensitivity inβ-Ga_(2)O_(3)photodetector

Polarization-sensitive photodetection and imaging have great application value in fields such as polarization division multiplexing optical communication,remote sensing,near-field imaging and military monitoring.Pursuing a high polarization ratio has always been the research hotspot in polarization-sensitive photodetectors.In this paper,we report a compression strain enhanced polarization ratio inβ-gallium oxide(β-Ga_(2)O_(3))single crystal flake.A rigorous crystallographic analysis confirmed its high crystalline quality and orientation.Angle-resolved polarization Raman spectroscopy(ARPRS)was adopted to study the anisotropy of its optical properties.Extensive ARPRS measurements and theoretical calculation consistently demonstrate the strong optical anisotropy in the high-qualityβ-Ga_(2)O_(3)flake.A polarization ratio of 0.96 was obtained in the flatβ-Ga_(2)O_(3)flake.Furthermore,mechanical strain of±0.7%was introduced intoβ-Ga_(2)O_(3).An increased polarization ratio of 0.98 was achieved in the case of 0.7%compression strain,which is,to the best of our knowledge,the highest value for UVC polarization-sensitive photodetectors.That corresponds to an improved polarization rejection ratio of 100.This work proposed a new path towards improving polarization sensitivity by applying strain engineering in the active material.

Flexible UV detectors based on in-situ hydrogen doped amorphous Ga_(2)O_(3) with high photo-to-dark current ratio

Amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))has been attracting more and more attention due to its unique merits such as wide bandgap(∼4.9 eV),low growth temperature,large-scale uniformity,low cost and energy efficient,making it a powerful competitor in flexible deep ultraviolet(UV)photodetection.Although the responsivity of the ever-reported a-Ga_(2)O_(3)UV photodetectors(PDs)is usually in the level of hundreds of A/W,it is often accompanied by a large dark current due to the presence of abundant oxygen vacancy(VO)defects,which severely limits the possibility to detect weak signals and achieve versatile applications.In this work,the VO defects in a-Ga_(2)O_(3)thin films are successfully passivated by in-situ hydrogen doping during the magnetron sputtering process.As a result,the dark current of a-Ga_(2)O_(3)UV PD is remarkably suppressed to 5.17×10^(-11) A at a bias of 5 V.Importantly,the photocurrent of the corresponding device is still as high as 1.37×10^(-3)A,leading to a high photo-to-dark current ratio of 2.65×107 and the capability to detect the UV light with the intensity below 10 nW cm^(-2).Moreover,the H-doped a-Ga_(2)O_(3)thin films have also been deposited on polyethylene naphtholate substrates to construct flexible UV PDs,which exhibit no great degradation in bending states and fatigue tests.These results demonstrate that hydrogen doping can effectively improve the performance of a-Ga_(2)O_(3)UV PDs,further promoting its practical application in various areas.

An innovative model for the transient response of a spherical thin-shell transducer and an experimental confirmation

A unique characteristic of piezoelectric materials is their ability of electric-mechanical transduction and converting mechanical energy to electrical energy or vice versa. This remarkable property, embedded in piezoelectric materials,has been exploited to construct a wide variety of

GaZn-VZn acceptor complex defect in Ga-doped ZnO

Gallium(Ga)-doped Zn O is regarded as a promising plasmonic material with a wide range of applications in plasmonics. In this study, zinc self-diffusion experiments are adopted to disclose the nature of the dominant compensating defect in Ga-doped Zn O isotopic heterostructures. The(Ga_(Zn)-V_(Zn))^- complex defect, instead of the isolated V_(Zn)^(2-), is identified as the predominant compensating acceptor center responsible for the low donor doping efficiency. The comparative diffusion experiments operated by the secondary ion mass spectrometry reveal a ~0.78 e V binding energy of this complex defect, which well matches the electrical activation energy derived from the temperature-dependent Hall effect measurements(^(0.82±0.02) e V). These findings contribute to an essential understanding of the(Ga_(Zn)-V_(Zn))^- complex defect and the potential engineering routes of heavily Ga-doped ZnO.

Surface plasmon enhanced solar-blind photoresponse of Ga2O3 film with Ga nanospheres

Semiconductor solar-blind(220-280 nm)photodetectors(PDs),which have important applications both in civil and military aspects,are mainly based on diamond[1],Al Ga N[2],Mg Zn O[3],and Ga_2O_3[4-11].Among these materials,Ga_2O_3has a direct band gap(~4.9 e V)just falling in solarblind spectral range,which makes Ga_2O_3a desirable candidate for solar-blind photodetection.Up to now,many kinds of Ga_2O_3PDs have been demonstrated including bulk[4,5],film[6-8]and nanostructures[9-11],as summarized in Table 1.From the summary,we can see although bulk