Device quality InAs/InGaAs multiple quantum well (MQW) structures were grown on InP substrates by metalorganic vapor phase epitaxy (MOVPE) and applied to lasers emitting at wavelengths longer than 2 mum. InAs/InGaAs MQWs with flat interfaces were obtained by adjusting the growth temperature between 460 degC and 510 degC. The photoluminescence peak wavelength of the MQWs increases from 1.93 to 2.47 mum as the thickness of InAs quantum wells increases from 2 to 7 nm. The structural and optical properties remained almost unchanged even after annealing at 620 degC. For 40-mu m-wide stripe broad-area lasers with 5-nm-thick InAs quantum wells, a lasing wavelength longer than 2.3 mum and an output power higher than 10 mW were achieved under continuous-wave operation at a temperature of 25 degC. These results indicate that InAs/InGaAs MQW structures grown by MOVPE are very useful for the active region of 2 mum wavelength lasers.