__ 59. The band gap in aluminum phosphide (AlP) is 2.5 electron-volts (1eV=1.6times 10^-19J) . What wavelength of light is emitted by an AIP diode? 60. An aluminum antimonide solid-state laser emits light with a wavelength of 730 . nm. Calculate the band gap in joules.

59. of light emitted by an AlP diode, we can use the equation:<br /><br />E = hc/λ<br /><br />Where:<br />E = energy (in joules)<br />h = Planck's constant (6.626 x 10^-34 J·s)<br />c = speed of light (3 x 10^8 m/s)<br />λ = wavelength (in meters)<br /><br />First, we need to convert the band gap from electron volts to joules:<br />E = 2.5 eV × 1.6 × 10^-19 J/eV = 4 × 10^-19 J<br /><br />Now, we can rearrange the equation to solve for the wavelength:<br />λ = hc/E<br /><br />Substituting the values, we get:<br />λ = (6.626 x 10^-34 J·s × 3 x 10^8 m/s) / 4 × 10^-19 J<br />λ = 4.97 × 10^-7 m or 497 nm<br /><br />Therefore, the wavelength of light emitted by an AlP diode is approximately 497 nm.<br /><br />60. To calculate the band gap in joules for an aluminum antimonide solid-state laser, we can use the same equation:<br /><br />E = hc/λ<br /><br />Given that the wavelength is 730 nm, we need to convert it to meters:<br />λ = 730 nm × 1 m/10^9 nm = 7.3 × 10^-7 m<br /><br />Now, we can substitute the values into the equation:<br />E = (6.626 x 10^-34 J·s × 3 x 10^8 m/s) / 7.3 × 10^-7 m<br />2 × 10^-19 J<br /><br />Therefore, the band gap in joules for an aluminum antimonide solid-state laser is approximately 2.71 × 10^-19 J.