Band Emission Peak Research Articles

Structural and luminescence properties of self-yellow emitting undoped and (Ca, Ba, Sr)-doped Zn2V2O7 phosphors synthesized by combustion method

A self-activated yellow emitting Zn2V2O7 was synthesized by combustion method. The influence of the processing parameters such as synthesis temperature and dopants concentration on the structure, morphology and luminescence properties was investigated. The X-ray diffraction (XRD) analysis confirmed that the samples have a tetragonal structure and no significant structural change was observed in varying both the synthesis temperature and the dopants concentration. The estimated average crystallite size was 78nm for the undoped samples synthesized at different temperatures and 77nm for the doped samples. Scanning electron microscope (SEM) images showed agglomerated hexagonal-shaped particles with straight edges at low temperatures and the shape of the particles changed to cylindrical structures at moderate temperatures. At higher temperatures, the morphology changed completely. However, the morphologies of the doped samples looked alike. The photoluminescence (PL) of the product exhibited broad emission bands ranging from 400 to 800nm. The best luminescence intensity was observed for the undoped Zn2V2O7 samples and those synthesized at 600 ℃. Any further increase in synthesis temperature, type and concentration of dopants led to a decrease in the luminescence intensity. The broad band emission peak of Zn2V2O7 consisted of two broad bands corresponding to emissions from the Em1 (3T2→1A1) and Em2 (3T1→1A1) transitions.

Enhanced photoluminescence property and broad color emission of ZnGa2O4 phosphor due to the synergistic role of Eu3+ and carbon dots

ZnGa2O4 phosphors co-composited with nanoscale carbon dots (CDs) and Eu3+ were presented for the tunable color emission. Novel single phase CDs or/and Eu3+ composited ZnGa2O4 phosphors were synthesized by microwave hydrothermal method and their optical properties were investigated. The ZnGa2O4 phosphors composited with CDs exhibited an intense broad blue light emission at 421 nm and a more enhanced photoluminescence intensity than those without CDs. The Eu3+ composited ZnGa2O4 phosphors gave an ideal red color emission. The CDs/Eu3+ co-composited ZnGa2O4 phosphors exhibited a wide emission band peak at 450 nm and narrow emission peak at 618 nm. Furthermore, the tunable color emissions of CDs/Eu3+ co-composited ZnGa2O4 phosphors from blue to the white light region, and then to red were obtained with the increasing Eu3+ concentration, which can be a promising single phased phosphor candidate in light emitting diodes. Broadly tunable emission single phased phosphor is tuned firstly through the synergistic role of the non-metal element and the rare earth metal ions.

Growth mechanisms of GaN epitaxial films grown on ex situ low-temperature AlN templates on Si substrates by the combination methods of PLD and MOCVD

Three kinds of ex situ low-temperature AlN (LT-AlN) templates grown on Si substrates by pulsed laser deposition (PLD) are employed to grow GaN epitaxial films by metal organic chemical vapor deposition (MOCVD). The single-crystalline ex situ LT-AlN template with smooth surface shows the greatest advantage to achieve high-quality GaN epitaxial films. It can effectively promote the lateral growth of high-temperature AlN layer to obtain coalesced and smooth surface, and therefore reduce the GaN nucleation energy barrier to facilitate GaN nucleation process. The as-grown truncated GaN nuclei with large sizes and low density are favorable for the two-dimensional growth of GaN. The ∼1.5 μm-thick GaN epitaxial film grown on this ex situ LT-AlN template shows a flat surface and the best crystalline quality with the minimum full-width at half maximums (FWHMs) of GaN(0002) and GaN(10–12) X-ray rocking curves (XRCs) as 504 and 566 arcsec, respectively, and the minimum FWHM of near band emission peak as 20.62 nm. According to the XRC results, compared with the GaN film grown without ex situ LT-AlN templates, the screw-type threading dislocations (TDs) density, edge- and mixed-type TDs density in as-grown GaN film are greatly reduced by 20% and 49%, respectively, proving the superiority of ex situ LT-AlN template. This work is instructional for the growth of high-quality nitride films by combination methods, and significant for achieving high-performance GaN-based devices.

Synthesis, structure, and luminescence properties of a novel double-perovskite Sr2LaNbO6:Mn4+ phosphor

A novel phosphor, Sr2LaNbO6:Mn4+, is synthesized by conventional solid-state reaction. The phosphor can be excited at 300–500nm and emit a deep-red light. An emission band peak of 694nm is observed from the spin-forbidden transition 2E→4A2 of Mn4+ ions. Energy transfer between the Mn4+–Mn4+ pairs decreases fluorescence decay time from 0.815ms to 0.512ms. The resistance of luminescence against thermal impact is also investigated by emission spectroscopy at heating temperatures from 300K to 500K. The calculated activation energy ΔE (∼0.345eV) demonstrate good thermal stability of the phosphors. All these results indicate that the phosphor can be applied in white-light-emitting diodes.

Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

Photoluminescence (PL) emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate) upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53–4.43eV but for a lower energy than 4.43eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28eV) to 400 (3.10eV) nm in step of 10nm and the corresponding photoluminescence (PL) emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL) bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280nm and have maximum at 290nm, thereafter they decrease and diminish at 360nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC), the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation.

Improvement in the Sensing Response of Nano-Crystalline ZnO-Based Hydrogen Sensor: Effect of Swift Heavy Ion Irradiation

Hydrogen gas sensing response of RF sputtered nano-crystalline ZnO thin film is improved by ~34.73% using swift heavy ion irradiation technique. X-ray diffraction reveals single crystalline wurtzite structure of ZnO thin films. Full width half maximum (FWHM) of (0002) diffraction peak is decreased with increase in ion fluences. However, at very high fluence 1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> ions/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , crystallinity is degraded while FWHM of diffraction peak increases. The ZnO films were grown under highly compressive stress, which was relaxed with incremental ion fluences up to 1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> ions/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Cathodoluminescence spectroscopy shows intense predominant peak around ~3.23 eV, which indicates good optical quality of the films. As ion fluence increases, a blue shift appears in near band emission peak from 3.23 to 3.33 eV, which indicates that in-plane stress is decreased. Surface morphology shows generation of self-affine nanostructure and grain fragments as ion fluences were increased. Grain fragmentations had enhanced the surface reaction, and as a result, gas sensor's relative response has improved. It was observed that the gas sensor's sensitivity is strongly dependent on ion fluences and operating temperature. The sensitivity was enhanced from 66.68% to 89.84% with fluence variations from pristine to 1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> ions/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 175 °C operating temperature.

ZnO films formed by atomic layer deposition as an optical biosensor platform for the detection of Grapevine virus A-type proteins

Novel sensitive optical biosensor for determination of Grapevine virus A-type (GVA) proteins (GVA-antigens) has been designed. This biosensor was based on thin films of Zinc Oxide (ZnO) deposited by atomic layer deposition (ALD). The ZnO-based films have demonstrated favorable surface-structural properties for the direct immobilization of antibodies against GVA-antigens in order to form a biosensitive layer sensitive to GVA-antigens. The immobilization was confirmed by intensity changes in the main near band emission (NBE) peak of ZnO and by the formation of intense photoluminescence band, discovered in the visible range around 425nm, caused by the immobilized proteins. The GVA-antigen detection was performed by the evaluation of changes and behavior of a corresponding luminescence band. The sensitivity of as-formed label-free biosensor towards the GVA-antigens was determined in the range from 1pg/ml to 10ng/ml; in addition, the selectivity of biosensor was evaluated.

Comparison study of transparent RF-sputtered ITO/AZO and ITO/ZnO bilayers for near UV-OLED applications

Hybrid inorganic/organic light-emitting diodes have attracted much attention in the field of luminescent electronics due to the desired incorporation of high optoelectronic features of inorganic materials with the processability and variety of organic polymers. To generate and emit a near ultraviolet (N-UV) ray, wide band gap semiconductors can be applied in the organic light-emitting diodes (OLEDs). In this paper, zinc oxide (ZnO) and aluminum-doped ZnO (AZO) thin films are deposited by radio frequency (RF) sputtering above the ITO electrode and poly [2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) conjugated polymer is utilized as a complementary p-type semiconductor in OLED structure. The impact of ZnO and AZO thickness on the structural, electrical, optical and morphological properties of ITO/AZO and ITO/ZnO bilayers are scrutinized and compared. Results show that with the enlargement of both ZnO and AZO film thickness, the physical properties are gradually improved resulting in the better quality of transparent conducting thin film. The average electrical resistivity of 8.4×10−4 and 1.1×10−3Ω-cm, average sheet resistance of 32.9 and 42.3Ω/sq, average transmittance of 88.3 and 87.3% and average FOM of 1.0×104 and 7.4×103 (Ω-cm)−1 are obtained for ITO/AZO and ITO/ZnO bilayers, respectively. Moreover, comparing the results indicates that the strain and the stress within the ITO/AZO bilayer are decreased nearly 19% with respect to ITO/ZnO bilayer which yield higher quality of crystal. Consequently, the physical properties of ITO/AZO bilayer is found to be superior regarding ITO/ZnO bilayer. For fabricated UV-OLEDs, the turn-on voltages, the characteristic energy (Et) and the total concentration of traps (Nt) for the devices with the structures of ITO/ZnO/MEH-PPV/Al and ITO/AZO/MEH-PPV/Al are obtained 12 and 14V, 0.108 and 0.191eV, 9.33×1016 and 5.22×1016cm−3, respectively. Furthermore, according to the electroluminescence (EL) spectra, the near band emission (NBE) peak for device with the structure of ITO/ZnO/MEH-PPV/Al is attained nearly in the wavelengths of 408nm which is in N-UV region. For ITO/AZO/MEH-PPV/Al, a slightly blue shift in NBE peak is observed due to the Burstein–Moss (BM) effect. Ultimately, different charge carrier transport mechanisms of fabricated UV-OLEDs have been carefully investigated.

The self-reduction ability of RE3+ in orthosilicate (RE = Eu, Tm, Yb, Sm): BaZnSiO4-based phosphors prepared in air and its luminescence

Nominal composition phosphors BaZnSiO4:RE (RE = Eu, Tm, Sm, Yb) were synthesized by the conventional solid-state method in air (oxidizing atmosphere, OA) and under 10%H2/90%N2 flow (reductive atmosphere, RA) conditions, respectively. Self-reduction phenomenon, which is a valence change from trivalent rare-earth ions (RE3+) to corresponding divalent state (RE2+) without reducing agent, were observed in the samples of Eu/Tm/Yb-doped BaZnSiO4 but have not observed in Sm-doped samples. Compared with RA condition, the ca. percent of the reductive concentration of Eu2+/Tm2+/Yb2+ in the phosphors BaZnSiO4 prepared in OA condition are 21%, 15% and 35%, respectively. It was found that both of BaZnSiO4:Eu and BaZnSiO4:Tm prepared in air show greatly broad band emission peak at 500 nm under the excitation of ultraviolet (UV), which indicated they are potential phosphors for UV-based LED. The factors which are related to self-reduction degree have been also discussed. The successful synthesis of BaZnSiO4:RE2+/3+ phosphors in air provides a new route to obtain other novel orthosilicate-based materials.

Microwave assisted synthesis of cubic Zirconia nanoparticles and study of optical and photoluminescence properties

Synthesis of pure ZrO2 nanoparticles in its cubic phase is a challenging task for the researchers. ZrO2 is a promising material and has received considerable attention recently due to superior properties that provide significant advantages in various applications like display systems and lighting. This paper discusses a better method of synthesis of pure ZrO2 nano crystals in cubic phase, free from impurities that alter the luminescence emissions. Studies on structural, optical and photoluminescence properties are reported. The structural studies show that as formed ZrO2 nanoparticles are in cubic phase. The crystallinity and phase formation of the samples were studied by XRD, the crystallinity increases as the calcination temperature increases. The samples are mesoporous and pore size decreases with increase in the calcination temperature as studied by BET. The optical energy band gap (Eg) was calculated and found to be 5.21eV for the as formed sample. As calcination temperature increases the increase in the optical band gap is observed. The PL spectra show an intense violet emission band peak centered at 387nm, due to the presence of the oxygen vacancies in the ZrO2 matrix. The crystallinity, particle size and the phase formation was further confirmed by HRTEM.

Cathodoluminescence study on the impurity behaviors at threading dislocations in GaN

The threading dislocations in GaN provide diffusion routes for impurity incorporation, which substantially influences GaN based optoelectronic devices. Here, we investigated the characteristics of the impurity incorporation at threading dislocations by HCl vapor phase etching and cathodoluminescence (CL) measurements. The distinctive etch pits induced by HCl vapor phase etching correspond definitely to different types of dislocations, and the etching process causes simultaneously H incorporation at a high temperature. CL spectra of the etch pits were analyzed, and the observed difference in the redshift of near band emission peak indicates that mix dislocations are more favorable for impurity incorporations than that of edge dislocations. The understanding on the impurity incorporation behavior at threading dislocations helps to obtain high quality GaN nanostructures.

Ionoluminescence study of Zn− and O− implanted ZnO crystals: An additional perspective

An investigation into the role of native point defects on the optical properties of ZnO using ion implantation, rapid thermal annealing (RTA) and ionoluminescence (IL) is presented. Low-energy (60keV) fixed-fluence (8×1015cm−2) Zn− and O− implantation has been used to directly introduce native point defects into ZnO single crystals. It is shown that annealing of implanted samples in Ar at T=1000°C for 2min amplifies the deep band emission (DBE) peak centered around 2.4eV while at the same time revealing subtle differences not clearly resolved in similar implanted samples treated under prolonged annealing. Particularly, a relative shift in the DBE peak maxima of the O and Zn doped samples subjected to RTA is observed. Gaussian decomposition of the IL spectra show distinct enhancements of the red (1.62eV) and yellow (2.15eV) emission bands in the O− implanted sample and the green (2.36eV) emission band in the Zn− implanted sample. Based on these results, and recent density functional theory (DFT) calculations, we have proposed a possible energy level scheme for some common ZnO native point defects.

Doping Ga effect on ZnO radio frequency sputtered films from a powder target

Undoped ZnO and ZnO:Ga films have been radio frequency (RF) sputtered on glass substrates using powder targets. X-ray diffraction studies reveal that the films are polycrystalline with a hexagonal wurtzite structure and a preferential orientation along the c-axis. The (002) peak shift to lower 2θ values indicates that the films suffered compressive stress with Ga incorporation. The grain sizes are found in the range of 20–23nm showing a nanostructure. All the films are highly transparent (>85%) in the visible region and the optical band gap shows a blue shift with Ga incorporation up to 3wt.% then a red shift with further Ga content from 3.56 to 3.47eV due to band tail. Urbach energy increases from 0.06 to 0.15eV with Ga content revealing disorder increase in the lattice.Besides the near band emission peak, which shows the same trend for the optical band gap variation, Photoluminescence measurements show deep level emissions in the violet, blue and green regions.The electrical parameters were obtained with both optical reflectance based on the Drude free-electron model and the Hall method and similar tendencies were observed within the two methods. The highest figure of merit observed in this study was 3.57×10−3Ω−1 showing that the 3wt.% ZnO:Ga films are potentially attractive for application as transparent conductive oxide thin films in solar cells. RF sputtering from a powder target was found to be a simple and cost effective technique for the synthesis of ZnO thin films for potential applications in the renewable energy devices.

Structural and luminescence properties of heavily doped radio-frequency-sputtered ZnTe:Cu thin films

We report on the structural and luminescence properties of ZnTe:Cu films containing Cu concentrations up to 12 at. % and prepared using rf magnetron sputtering. The lattice parameters of the various crystalline phases prevailing at different Cu concentrations (cubic, hexagonal, and orthorhombic) are calculated and compared with literature results on films prepared using other techniques. Study of the steady state photoluminescence and excitation spectra revealed the presence of three donor impurities involved in the well-known band at ∼1.70 eV (peak L) attributed to self-activated transition. One of these donors is merging partially with the conduction band and the two others have mutually overlapping density of states with maxima at 0.29 eV and 0.45 eV below the conduction band edge. Another donor that is resonant with the conduction continuum is responsible for a higher energy emission band (peak H). The density of states of this donor has a maximum at 0.57 eV above the conduction band edge for a copper concentration of 8.2 at. %. The emission peak H undergoes a blue shift and its intensity increases sharply relative to the intensity of the L peak with the increase of Cu concentration. Moreover, the H emission extends to photon energies higher than the band gap. A possible interpretation of the behaviour of the peak H in terms of recombination involving the resonant states is suggested.

Inherent photoluminescence Stokes shift in GaAs

The intrinsic photoluminescence Stokes shift, i.e., the energy difference between optical band gap and emission peak, of 350 μm thick semi-insulating GaAs wafers is found to be 4 meV at room temperature. The result is based on the determination of the optical bulk band gap from the transmission trend via modified Urbach rule whose result is confirmed with the transmission derivative method. The findings reveal the detailed balance of the optically evoked transitions and disclose the intrinsic link between Stokes shift and the Urbach tail slope parameter.

Influence of Cu doping on the microstructure, optical properties and photoluminescence features of Cd0.9Zn0.1S nanoparticles

Cd0.9−xZn0.1CuxS (0≤x≤0.06) nanoparticles were successfully synthesized by a conventional chemical co-precipitation method at room temperature. Crystalline phases and optical absorption of the nanoparticles have been studied by X-ray diffraction (XRD) and UV–visible spectrophotometer. XRD confirms the phase singularity of the synthesized material, which also confirmed the formation of Cd–Zn–Cu–S alloy nanocrystals rather than separate nucleation or phase formation. Elemental composition was examined by the energy dispersive X-ray analysis and the microstructure was examined by scanning electron microscope. The blue shift of absorption edge below Cu=2% is responsible for dominance of Cu+ while at higher Cu concentration dominated Cu2+, d–d transition may exist. It is suggested that the addition of third metal ion (Cu2+/Cu+) is an effective way to improve the optical property and stability of the Cd0.9Zn0.1S solid solutions. When Cu is introduced, stretching of Cd–Zn–Cu–S bond is shifted lower wave number side from 678cm−1 (Cu=0%) to 671cm−1 (Cu=6%) due to the presence of Cu in Cd–Zn–S lattice and also the size effect. The variation in blue band emission peak from 456nm (∼2.72eV) to 482nm (∼2.58eV) by Cu-doping is corresponding to the inter-band radiation combination of photo-generated electrons and holes. Intensity of red band emission centered at 656nm significantly increased up to Cu=4%; beyond 4% it is decreased due to the quenching of Cu concentration.

SPATIALLY RESOLVED l -C 3 H + EMISSION IN THE HORSEHEAD PHOTODISSOCIATION REGION: FURTHER EVIDENCE FOR A TOP-DOWN HYDROCARBON CHEMISTRY

Small hydrocarbons, such as C2H, C3H and C3H2 are more abundant in photo-dissociation regions (PDRs) than expected based on gas-phase chemical models. To explore the hydrocarbon chemistry further, we observed a key intermediate species, the hydrocarbon ion l-C3H+, in the Horsehead PDR with the Plateau de Bure Interferometer at high-angular resolution (6''). We compare with previous observations of C2H and c-C3H2 at similar angular resolution and new gas-phase chemical model predictions to constrain the dominant formation mechanisms of small hydrocarbons in low-UV flux PDRs. We find that, at the peak of the HCO emission (PDR position), the measured l-C3H+, C2H and c-C3H2 abundances are consistent with current gas-phase model predictions. However, in the first PDR layers, at the 7.7 mum PAH band emission peak, which are more exposed to the radiation field and where the density is lower, the C2H and c-C3H2 abundances are underestimated by an order of magnitude. At this position, the l-C3H+ abundance is also underpredicted by the model but only by a factor of a few. In addition, contrary to the model predictions, l-C3H+ peaks further out in the PDR than the other hydrocarbons, C2H and c-C3H2. This cannot be explained by an excitation effect. Current gas-phase photochemical models thus cannot explain the observed abundances of hydrocarbons, in particular in the first PDR layers. Our observations are consistent with a top-down hydrocarbon chemistry, in which large polyatomic molecules or small carbonaceous grains are photo-destroyed into smaller hydrocarbon molecules/precursors.

Effect of pH variation on structural and optical properties of Zn0.95Co0.05O nanoparticles

We have synthesized the Zn0.95Co0.05O nanoparticles using a sol–gel method with different pH values under acid base and basic base reactions. The structural properties were characterized using powder X-ray diffraction (XRD) and scanning electron microscope (SEM) while the optical properties were characterized using Ultraviolet/Visible (UV/Vis) spectroscopy, Fourier transform infra red (FTIR) spectroscopy and Raman spectroscopy. Both samples are found in single phase with wurtzite structure. SEM micrographs show spherical nanoparticles for the sample synthesized under acid base reaction (pH=6) and nanorods for the sample synthesized under basic base reaction (pH=9). The band gap estimated using UV/Vis spectra shows an increase with the increase in pH value. FTIR spectra show that typical stretching mode peak of ZnO at 497cm−1. On Co doping this absorption peak shifted to 446cm−1 (for pH=6 sample) and to 478cm−1 (for pH=9 sample). Raman spectra of cobalt doped samples reveal presence of small amounts of ZnCo2O4 and Co3O4. Fluorescence spectra display blue shift in near band emission peak of ZnO with cobalt doping and pH variation.

Structural, compositional, and photoluminescence characterization of thermal chemical vapor deposition-grown Zn3N2 microtips

The catalytic growth of Zn3N2 using guided-stream thermal chemical vapor deposition has been investigated within the parameter range of acicular growth to obtain uniform microtips with a high crystalline quality. The cubic anti-bixbyite crystal structure of Zn3N2 microtips and its related phonon mode are revealed by X-ray diffraction and Raman spectroscopy, respectively. The surface morphologies of pure and surface-oxidized Zn3N2 microtips are depicted by scanning electron microscopy and show the crack formation on the surface-oxidized Zn3N2 microtips. The spatial element distribution map confirms the VLS growth mechanism for Zn3N2 microtips and reveals the depth profile of zinc, nitrogen, oxygen, and nickel elements. Photoluminescence (PL) spectra of Zn3N2 microtips show a sharp infrared band-to-band emission peak at 1.34 eV with a full width at half maximum of ∼100 meV and a very broad oxygen-related defect band emission peak centered at ∼0.85 eV.

OH Meinel band nightglow profiles from OSIRIS observations

AbstractThe mesospheric nightglow spectrum is replete with OH Meinel band emissions, from the midvisible to the midinfrared. These emissions provide a wealth of aeronomic information, giving a physical view of the chemistry and dynamics of the upper atmosphere. The Optical Spectrograph and Infrared Imaging System (OSIRIS) instrument, on the Odin satellite, is currently one of the few satellite instruments that simultaneously observes emissions from multiple and separate Meinel bands. This has allowed the derivation of near‐global data sets of nighttime OH volume emission rate profiles for the Meinel (5‐1), (8‐3), and (9‐4) bands. The 2002–2013 climatologies consistently show that emission from bands in higher upper vibrational levels peaks at higher altitudes. The global average (5‐1), (8‐3), and (9‐4) band emission peak heights are at altitudes of 86.0 km, 86.7 km, and 87.1 km, respectively. The 1σ variation in the (5‐1), (8‐3), and (9‐4) band, peak heights are 1.8 km, 1.9 km, and 1.9 km, respectively. The climatological (30 day, 10° latitude) peak heights can vary significantly with both time and latitude; however, the (5‐1) band climatological peak height is nearly always below that of the (8‐3) band, which is nearly always below that of the (9‐4) band. The temporal variation in the emission peak height can have a significant impact on measurements of OH rotational temperatures from ground‐based observations of the OH layer. It was found that omitting the profile climatology can bias a ground‐based temperature measurement by as much as ±4 K and can also make ground‐based measurements susceptible to nonrealistic temperature variations.